The author decidedly has expert syndrome -- they deny both the history and rational behind memory units nomenclature. Memory measurements evolved utilizing binary organizational patterns used in computing architectures. While a proud French pedant might agree with the decimal normalization of memory units discussed, it aligns more closely to the metric system, and it may have benefits for laypeople, it fails to account for how memory is partitioned in historic and modern computing.
They are managed by different standards organizations. One doesn't like the other encroaching on its turf. "kilo" has only one official meaning as a base-10 scalar.
What are you talking about? The article literally fully explains the rationale, as well as the history. It's not "denying" anything. Seems entirely reasonable and balanced to me.
They are definitely denying the importance of 2-fold partitioning in computing architectures. VM_PAGE_SIZE is not defined with the value of '10000' for good reason (in many operating systems it is set to '16384').
That's why I said "usually acceptable depending on the context". In spoken language I also don't like the awkward and unusual pronunciation of "kibi". But I'll still prefer to write in KiB, especially if I document something.
Also If you open major Linux distro task managers, you'll be surprised to see that they often show in decimal units when "i" is missing from the prefix. Many utilities often avoid the confusing prefixes "KB", "MB"... and use "KiB", "MiB"...
A mile is exactly 1000 paces, or 4000 feet. You may disagree, but consider: the word mile come from latin for "one thousand". Therefore a mile must be 1000 of something, namely paces. I hope you find this argument convincing.
And a megabyte is depending on the context precisely 1000x1000=1,000,000 or 1024x1024=1,048,576 bytes*, except when you're talking about the classic 3.5 inch floppy disks, where "1.44 MB" stands for 1440x1024 bytes, or about 1.47 true MB or 1.41 MiB.
* Yeah, I read the article. Regardless of the IEC's noble attempt, in all my years of working with people and computers I've never heard anyone actually pronounce MiB (or write it out in full) as "mebibyte".
Well the 1.44 MB, was called that because it was 1440 KB, twice the capacity of the 720k floppy, and 4x the 360k floppy. It made perfect sense to me at that time.
It may "make sense" but that's actually a false equivalence. The raw disk space for a 3.5" high-density floppy disk for IBM PCs is 512 bytes per sector * 18 sectors per track * 80 tracks per side * 2 sides = 1,474,560 bytes. It is 1.47 MB or 1.40 MiB neither of which is 1440 KB or KiB. The 1440 number comes from Microsoft's FAT12 filesystem. That was the space that's left for files outside the allocation table.
Sectors per track or tracks per side is subject to change. Moreover a different filesystem may have non-linear growth of the MFT/superblock that'll have a different overhead.
I worked with networked attached storage systems at pib scale several years ago and we referred to things in gib/tib because it was significant when referring to the size of systems and we needed to be precise.
That being said, I think the difference between mib and mb is niche for most people
All words are made up. They weren’t handed down from a deity, they were made up by humans to communicate ideas to other humans.
“Kilo” can mean what we want in different contexts and it’s really no more or less correct as long as both parties understand and are consistent in their usage to each other.
I find it concerning that kilo can mean both 10^3 and 2^10 depending on context.
And that the context is not if you're speaking about computery stuff, but which program you use has almost certainly lead to avoidable bugs.
That latter part is only true since marketing people decided they knew better about computer related things than computer people.
It's also stupid because it's rare than anyone outside of programming even needs to care exactly how many bytes something else. At the scales that each of kilobyte, megabyte, gigabyte, terabyte etc are used, the smaller values are pretty much insignificant details.
If you ask for a kilogram of rice, then you probably care more about that 1kg of rice is the same as the last 1kg of rice you got, you probably wouldn't even care how many grams that is. Similarly, if you order 1 ton of rice, you do care exactly how many grams it is, or do you just care that this 1 ton is the same as that 1 ton?
This whole stupidity started because hard disk manufacturers wanted to make their drives sound bigger than they actually were. At the time, everybody buying hard disks knew about this deception and just put up with it. We'd buy their 2GB drive and think to ourselves, "OK so we have 1.86 real GB". And that was the end of it.
Can you just imagine if manufacturers started advertising computers as having 34.3GB of RAM? Everybody would know it was nonsense and call it 32GB anyway.
> Yes, and the made up words of kilo and kibi were given specific definitions by the people who made them up
Kilo was generally understood to mean one thousand long before it was adopted by a standards committee. I know the French love to try and prescribe the use of language, but in most of the world words just mean what people generally understand them to mean; and that meaning can change.
> Yes, and the made up words of kilo and kibi were given specific definitions by the people who made them up
Good for them. People make up their own definitions for words all the time. Some of those people even try to get others to adopt their definition. Very few are ever successful. Because language is about communicating shared meaning. And there is a great deal of cultural inertia behind the kilo = 2^10 definition in computer science and adjacent fields.
I don't think that the xkcd is relevant here, because I'm arguing that both parties know what the other is talking about. I haven't implicitly changed the definition because most people assume that kilobyte is 1024 bytes. Yeah, sure, it's "wrong" in some sense, but language is about communicating ideas between two people; if the communication is successful than the word is "correct".
If Bob says "kilobyte" to Alice, and Bob means 5432 bytes, and Alice perceives him to mean 5432 bytes, then in that context, "kilobyte" means 5432 bytes.
I had a computer architecture prof (a reasonably accomplished one, too) who thought that all CS units should be binary, e.g. Gigabit Ethernet should be 931Mbit/s, not 1000MBit/s.
I disagreed strongly - I think X-per-second should be decimal, to correspond to Hertz. But for quantity, binary seems better. (modern CS papers tend to use MiB, GiB etc. as abbreviations for the binary units)
Fun fact - for a long time consumer SSDs had roughly 7.37% over-provisioning, because that's what you get when you put X GB (binary) of raw flash into a box, and advertise it as X GB (decimal) of usable storage. (probably a bit less, as a few blocks of the X binary GB of flash would probably be DOA) With TLC, QLC, and SLC-mode caching in modern drives the numbers aren't as simple anymore, though.
RAM had binary sizing for perfectly practical reasons. Nothing else did (until SSDs inherited RAM's architecture).
We apply it to all the wrong things mostly because the first home computers had nothing but RAM, so binary sizing was the only explanation that was ever needed. And 50 years later we're sticking to that story.
RAM having binary sizing is a perfectly good reason for hard drives having binary sized sectors (more efficient swap, memory maps, etc), which in turn justifies all of hard disks being sized in binary.
Nope. The first home computers like the C64 had RAM and sectors on disc, which in case of the C64 means 256 bytes. And there it is again, the smaller base of 1024.
Just later, some marketing assholes thought they could better sell their hard drives when they lie about the size and weasel out of legal issues with redefining the units.
There's a good reason that gigabit ethernet is 1000MBit/s and that's because it was defined in decimal from the start. We had 1MBit/s, then 10MBit/s, then 100MBit/s then 1000MBit/s and now 10Gbit/s.
Interestingly, from 10GBit/s, we now also have binary divisions, so 5GBit/s and 2.5GBit/s.
Even at slower speeds, these were traditionally always decimal based - we call it 50bps, 100bps, 150bps, 300bps, 1200bps, 2400bps, 9600bps, 19200bps and then we had the odd one out - 56k (actually 57600bps) where the k means 1024 (approximately), and the first and last common speed to use base 2 kilo. Once you get into MBps it's back to decimal.
This has nothing to do with the 1024, it has todo with the 1200 and the multiples of it and the 14k and 28k modems where everyone just cut off the last some hundred bytes because you never reached that speed anyway.
Wirespeeds and bitrate and baud and all that stuff is vastly confusing when you start looking into it - because it's hard to even define what a "bit on the wire" is when everything has to be encoded in such a way that it can be decoded (specialized protocols can go FASTER than normal ones on the same wire and the same mechanism if they can guarantee certain things - like never having four zero bits in a row).
musicians use numbering systems that are actually far more confused than anything discussed here. how many notes in an OCTave? "do re mi fa so la ti do" is eight, but that last do is part of the next octave, so an OCTave is 7 notes. (if we count transitions, same thing, starting at the first zero do, re is 1, ... again 7.
the same and even more confusion is engendered when talking about "fifths" etc.
The 7 note scale you suggest (do re mi fa so la ti do) is comprised of different intervals (2 2 1 2 2 2 1) in the 12-fold equal tempered scale. There are infinite ways of exploring an octave in music, but unfortunately listener demand for such exploration is near infinitesimal.
You can blame the Romans for that, as they practiced inclusive counting. Their market days occurring once every 8 days were called nundinae, because the next market day was the ninth day from the previous one. (And by the same logic, Jesus rose from the dead on the third day.)
An even bigger problem is that networks are measured in bits while RAM and storage are in bytes. I'm sure this leads to plenty of confusion when people see a 120 meg download on their 1 gig network.
(The old excuse was that networks are serial but they haven't been serial for decades.)
Whenever this discussion comes up I liked to point out that even in the computer industry, prefixes like kilo/mega/etc more often mean a power of 10 than a power of 2:
Nice page, and nice link to Colin Percival's page too! Let me toss you one example: CDs are marketed in mebibytes. A "650 MB" burnable CD is actually 650 MiB ≈ 682 MB, and likewise for "700 MB" being actually 700 MiB ≈ 734 MB. DVD and BD do use metric prefixes correctly, like you pointed out. Back in the day, I archived my data on CD/DVD/BD, and I planned out my disc burns to have only about 1 to 10 MB of wasted space, so I had to be very aware of the true definition and exactly how much capacity was available for me to use.
They almost always mean power of 10, unless you're discussing RAM, RAM addressing, or RAM pages. (or flash, which has inherited most of the same for most of the same reasons)
> The only few places where binary prefixes are used are to refer to RAM capacity and file sizes, whereas decimal prefixes apply to all other areas and all units (not "only bitrates"): storage capacity, clock frequency, stream bandwidth, baud, pixel numbers, data throughput, processing power
Storage capacity also uses binary prefixes. The distinction here isn't that file sizes are reported in binary numbers and storage capacity is reported in decimal numbers. It's that software uses binary numbers and hard drive manufacturers use decimal numbers. You don't see df reporting files in binary units and capacities in decimal units.
Of that large list of measurements, only bandwidth is measured in bytes, making the argument mostly an exercise in sophistry. You can't convince anyone that KB means 1000 bytes by arguing that kHz means 1000 Hz.
I'm sticking with power-of-2 sizes. Invent a new word for decimal, metric units where appropriate. I proposed[0] "kitribytes", "metribytes", "gitribytes", etc. Just because "kilo" has a meaning in one context doesn't mean we're stuck with it in others. It's not as though the ancient Greeks originally meant "kilo" to mean "exactly 1,000". "Giga" just meant "giant". "Tera" is just "monster". SI doesn't have sole ownership for words meaning "much bigger than we can possibly count at a glance".
Donald Knuth himself said[1]:
> The members of those committees deserve credit for raising an important issue, but when I heard their proposal it seemed dead on arrival --- who would voluntarily want to use MiB for a maybe-byte?! So I came up with the suggestion above, and mentioned it on page 94 of my Introduction to MMIX. Now to my astonishment, I learn that the committee proposals have actually become an international standard. Still, I am extremely reluctant to adopt such funny-sounding terms; Jeffrey Harrow says "we're going to have to learn to love (and pronounce)" the new coinages, but he seems to assume that standards are automatically adopted just because they are there.
If Gordon Bell and Gene Amdahl used binary sizes -- and they did -- and Knuth thinks the new terms from the pre-existing units sound funny -- and they do -- then I feel like I'm in good company on this one.
Knuth is not in favour of using kilo/mega/etc with power-of-2 meanings:
> I'm a big fan of binary numbers, but I have to admit that this convention flouts the widely accepted international standards for scientific prefixes.
He also calls it “an important issue” and had written “1000 MB = 1 gigabyte (GB), 1000 GB = 1 terabyte (TB), 1000 TB = 1 petabyte (PB), 1000 PB = 1 exabyte (EB), 1000 EB = 1 zettabyte (ZB), 1000 ZB = 1 yottabyte (YB)” in his MMIX book even before the new binary prefixes became an international standard.
He is merely complaining that the new names for the binary prefixes sound funny (and has his own proposal like “large megabyte” and notation MMB etc), but he's still using the kilo/mega/etc prefixes with decimal meanings.
> Invent a new word for decimal, metric units where appropriate.
No, they already did the opposite with KiB, MiB.
Because most metric decimal units are used for non-computing things. Kilometers, etc. Are you seriously proposing that kilometers should be renamed kitrimeters because you think computing prefixes should take priority over every other domain of science and life?
Do you often convert between inherently binary units like RAM sizes and more appropriately decimal units like distances?
It would be annoying of one frequently found themselves calculating gigabytes per hectare. I don't think I've ever done that. The closest I've seen is measure magnetic tape density where you get weird units like "characters per inch", where neither "character" nor "inch" are the common units for their respective metrics.
It means that is fine for Kilo to mean 1024 in the context of computers and 1000 in the context of distances, because you're never going to be in a situation where that is ambiguous.
Except it's not because it's constantly ambiguous in computing.
E.g. Macs measure file sizes in powers of 10 and call them KB, MB, GB. Windows measures file sizes in powers of 2 and calls them KB, MB, GB instead of KiB, MiB, GiB. Advertised hard drives come in powers of 10. Advertised memory chips come in powers of 2.
When you've got a large amount of data or are allocating an amount of space, are you measuring its size in memory or on disk? On a Mac or on Windows?
The author doesn’t actually answer their question, unless I missed something?
They go on to make a few more observations, and say finally only that the current different definitions are sometimes confusing, to non experts.
I don’t see much of an argument here for changing anything. Some non experts experience minor confusion about two things that are different, did I miss something bigger in this?
"kilo" means what people take it to mean in any particular context. In computing, it is overwhelmingly power of two even today, and if you don't use it in this manner you have to clarify to be understood properly.
> Explorer is just following existing practice. Everybody (to within experimental error) refers to 1024 bytes as a kilobyte, not a kibibyte. If Explorer were to switch to the term kibibyte, it would merely be showing users information in a form they cannot understand, and for what purpose? So you can feel superior because you know what that term means and other people don’t.
The meaning of kilo, mega, giga, tera, etc. are unambiguous: SI prefixes defined as powers of 10, not 2. 1 TB is 10*12 bytes, not 2*40 bytes.
The misuse of those prefixes as powers of 1024, while useful as shorthand for computer memory where binary addressing means, is still exactly that: a misuse of SI prefixes.
There's now a separate set of base-2 prefixes to solve this, and people need to update their language accordingly.
Just because an official body gives a single definition doesn't mean it's unambiguous. Real communication isn't bound by official bodies. When I say my computer has 16GB of RAM, that does not mean exactly 16 billion bytes.
I need to update my language accordingly? No thanks. I'll keep saying what I say and nothing will happen.
This ambiguity is documented at least back to 1984, by IBM, the pre-eminent computer company of the time.
In 1972 IBM started selling the IBM 3333 magnetic disk drive. This product catalog [0] from 1979 shows them marketing the corresponding disks as "100 million bytes" or "200 million bytes" (3336 mdl 1 and 3336 mdl 11, respectively). By 1984, those same disks were marketed in the "IBM Input/Output Device Summary"[1] (which was intended for a customer audience) as "100MB" and "200MB"
Edit: The below is wrong. Older experience has corrected me - there has always been ambiguity (perhaps bifurcated between CPU/OS and storage domains). "And that with such great confidence!", indeed.
-------
The article presents wishful thinking. The wish is for "kilobyte" to have one meaning. For the majority of its existence, it had only one meaning - 1024 bytes. Now it has an ambiguous meaning. People wish for an unambiguous term for 1000 bits, however that word does not exist. People also might wish that others use kibibyte any time they reference 1024 bytes, but that is also wishful thinking.
The author's wishful thinking is falsely presented as fact.
I think kilobyte was the wrong word to ever use for 1024 bytes, and I'd love to go back in time to tell computer scientists that they needed to invent a new prefix to mean "1,024" / "2^10" of something, which kilo- never meant before kilobit / kilobyte were invented. Kibi- is fine, the phonetics sound slightly silly to native English speakers, but the 'bi' indicates binary and I think that's reasonable.
I'm just not going to fool myself with wishful thinking. If, in arrogance or self-righteousness, one simply assumes that every time they see "kilobyte" it means 1,000 bytes - then they will make many, many failures. We will always have to take care to verify whether "kilobyte" means 1,000 or 1,024 bytes before implementing something which relies on that for correctness.
You've got it exactly the wrong way around. And that with such great confidence!
There was always a confusion about whether a kilobyte was 1000 or 1024 bytes. Early diskettes always used 1000, only when the 8 bit home computer era started was the 1024 convention firmly established.
Before that it made no sense to talk about kilo as 1024. Earlier computers measured space in records and words, and I guess you can see how in 1960, no one would use kilo to mean 1024 for a 13 bit computer with 40 byte records. A kiloword was, naturally, 1000 words, so why would a kilobyte be 1024?
1024 bearing near ubiquitous was only the case in the 90s or so - except for drive manufacturing and signal processing. Binary prefixes didn't invent the confusion, they were a partial solution. As you point out, while it's possible to clearly indicate binary prefixes, we have no unambiguous notation for decimal bytes.
Even worse, the 3.5" HD floppy disk format used a confusing combination of the two. Its true capacity (when formatted as FAT12) is 1,474,560 bytes. Divide that by 1024 and you get 1440KB; divide that by 1000 and you get the oft-quoted (and often printed on the disk itself) "1.44MB", which is inaccurate no matter how you look at it.
I'm not seeing evidence for a 1970s 1000-byte kilobyte. Wikipedia's floppy disk page mentions the IBM Diskette 1 at 242944 bytes (a multiple of 256), and then 5¼-inch disks at 368640 bytes and 1228800 bytes, both multiples of 1024. These are sector sizes. Nobody had a 1000-byte sector, I'll assert.
The wiki page agrees with parent, "The double-sided, high-density 1.44 MB (actually 1440 KiB = 1.41 MiB or 1.47 MB) disk drive, which would become the most popular, first shipped in 1986"
it's, way older in than the 1990's! In computering, "K" always meant 1024 at least from 1970's.
Example: in 1972, DEC PDP 11/40 handbook [0] said on first page: "16-bit word (two 8-bit bytes), direct addressing of 32K 16-bit words or 64K 8-bit bytes (K = 1024)". Same with Intel - in 1977 [1], they proudly said "Static 1K RAMs" on the first page.
It was exactly this - and nobody cared until the disks (the only thing that used decimal K) started getting so big that it was noticeable. With a 64K system you're talking 1,536 "extra" bytes of memory - or 1,536 bytes of memory lost when transferring to disk.
But once hard drives started hitting about a gigabyte was when everyone started noticing and howling.
It was earlier than the 90s, and came with popular 8-bit CPUs in the 80s. The Z-80 microprocessor could address 64kb (which was 65,536 bytes) on its 16-bit address bus.
Similarly, the 4104 chip was a "4kb x 1 bit" RAM chip and stored 4096 bits. You'd see this in the whole 41xx series, and beyond.
> The Z-80 microprocessor could address 64kb (which was 65,536 bytes) on its 16-bit address bus.
I was going to say that what it could address and what they called what it could address is an important distinction, but found this fun ad from 1976[1].
"16K Bytes of RAM Memory, expandable to 60K Bytes", "4K Bytes of ROM/RAM Monitor software", seems pretty unambiguous that you're correct.
Interestingly wikipedia at least implies the IBM System 360 popularized the base-2 prefixes[2], citing their 1964 documentation, but I can't find any use of it in there for the main core storage docs they cite[3]. Amusingly the only use of "kb" I can find in the pdf is for data rate off magnetic tape, which is explicitly defined as "kb = thousands of bytes per second", and the only reference to "kilo-" is for "kilobaud", which would have again been base-10. If we give them the benefit of the doubt on this, presumably it was from later System 360 publications where they would have had enough storage to need prefixes to describe it.
Still the advertisement is filled with details like the number of chips, the number of pins, etc. If you're dealing with chips and pins, it's always going to base-2.
only when the 8 bit home computer era started was the 1024 convention firmly established.
That's the microcomputer era that has defined the vast majority of our relationship with computers.
IMO, having lived through this era, the only people pushing 1,000 byte kilobytes were storage manufacturers, because it allows them to bump their numbers up.
Good lord, arrogance and self-righteousness? You're blowing the article out of proportion. They don't say anything non-factual or unreasonable - why inject hostility where none is called for?
In fact, they practically say the same exact thing you have said: In a nutshell, base-10 prefixes were used for base-2 numbers, and now it's hard to undo that standard in practice. They didn't say anything about making assumptions. The only difference is that that the author wants to keep trying, and you don't think it's possible? Which is perfectly fine. It's just not as dramatic as your tone implies.
I'm not calling the author arrogant or self-righteous. I stated that if a hypothetical person simply assumes that every "kilobyte" they come across is 1,000 bytes, that they are doomed to frequent failures. I implied that for someone to hypothetically adhere to that internal dogma even in the face of impending failures, the primary reasons would be either arrogance or self-righteousness.
I don't read any drama or hostility, just a discussion about names. OP says that kilobyte means one thing, the commenter says that it means two things and just saying it doesn't can't make that true. I agree, after all, we don't get to choose the names for things that we would like.
> The article presents wishful thinking. The wish is for "kilobyte" to have one meaning. For the majority of its existence, it had only one meaning - 1024 bytes. Now it has an ambiguous meaning. People wish for an unambiguous term for 1000 bits, however that word does not exist. People also might wish that others use kibibyte any time they reference 1024 bytes, but that is also wishful thinking.
> The author's wishful thinking is falsely presented as fact.
There's good reason why the meanings of SI prefixes aren't set by convention or by common usage or by immemorial tradition, but by the SI. We had several thousand years of setting weights and measures by local and trade tradition and it was a nightmare, which is how we ended up with the SI. It's not a good show for computing to come along and immediately recreate the long and short ton.
> setting weights and measures by local and trade tradition and it was a nightmare
Adding to your point, it is human nature to create industry- or context-specific units and refuse to play with others.
In the non-metric world, I see examples like: Paper publishing uses points (1/72 inch), metal machinists use thousands of an inch, woodworkers use feet and inches and binary fractions, land surveyors use decimal feet (unusual!), waist circumference is in inches, body height is in feet and inches, but you buy fabric by the yard, airplane altitudes are in hundreds to tens of thousands of feet instead of decimal miles. Crude oil is traded in barrels but gasoline is dispensed in gallons. Everyone thinks their usage of units and numbers is intuitive and optimal, and everyone refuses to change.
In the metric(ish) world, I still see many tensions. The micron is a common alternate name for the micrometre, yet why don't we have a millin or nanon or picon? The solution is to eliminate the micron. I've seen the angstrom (0.1 nm) in spectroscopy and in the discussion of CPU transistor sizes, yet it diverts attention away from the picometre. The bar (100 kPa) is popular in talking about things like tire pressure because it's nearly 1 atmosphere. The mmHg is a unit of pressure that sounds metric but is not; the correct unit is pascal. No one in astronomy uses mega/giga/tera/peta/etc.-metres; instead they use AU and parsec and (thousand, million, billion) light-years. Particle physics use eV/keV/MeV instead of some units around the picojoule.
Having a grab bag of units and domains that don't talk to each other is indeed the natural state of things. To put your foot down and say no, your industry does not get its own special snowflake unit, stop that nonsense and use the standardized unit - that takes real effort to achieve.
The SI should just have set kilobyte to 1024 in acquiescence to the established standard, instead of being defensive about keeping a strict meaning of the prefix.
It goes back way further than that. The first IBM harddrive was the IBM 350 for the IBM 305 RAMDAC. It was 5 million characters. Not bytes, bytes weren't "a thing" yet. 5,000,000 characters. The very first harddrive was base-10.
Here's my theory. In the beginning, everything was base10. Because humans.
Binary addressing made sense for RAM. Especially since it makes decoding address lines into chip selects (or slabs of core, or whatever) a piece of cake, having chips be a round number in binary made life easier for everyone.
Then early DOS systems (CP/M comes to mind particularly) mapped disk sectors to RAM regions, so to enable this shortcut, disk sectors became RAM-shaped. The 512-byte sector was born. File sizes can be written in bytes, but what actually matters is how many sectors they take up. So file sizing inherited this shortcut.
But these shortcuts never affected "real computers", only the hamstrung crap people were running at home.
So today we have multiple ecosystems. Some born out of real computers, some with a heavy DOS inheritance. Some of us were taught DOS's limitations as truth, and some of us weren't.
However it doesn't seem to be divided into sectors at all, more like each track is like a loop of magnetic tape. In that context it makes a bit more sense to use decimal units, measuring in bits per second like for serial comms.
Or maybe there were some extra characters used for ECC? 5 million / 100 / 100 = 500 characters per track, leaves 72 bits over for that purpose if the actual size was 512.
First floppy disks - also from IBM - had 128-byte sectors. IIRC, it was chosen because it was the smallest power of two that could store an 80-column line of text (made standard by IBM punched cards).
Disk controllers need to know how many bytes to read for each sector, and the easiest way to do this is by detecting overflow of an n-bit counter. Comparing with 80 or 100 would take more circuitry.
Almost all computers have used power-of-2 sized sectors. The alternative would involve wasted bits (e.g. you can't store as much information in 256 1000-byte units as 256 1024-byte units, so you lose address space) or have to write multiplies and divides and modulos in filesystem code running on machines that don't have opcodes for any of those.
You can get away with those on machines with 64 bit address spaces and TFLOPs of math capacity. You can't on anything older or smaller.
Which doesn't make it more correct, of course, even through I strongly believe believe that it is (where appropriate for things like memory sizes). Just saying, it goes much further back than 1984.
And networking - we've almost always used standard SI prefixes for, e.g., bandwidth. 1 gigabit per second == 1 * 10^9.
Which makes it really @#ing annoying when you have things like "I want to transmit 8 gigabytes (meaning gibibytes, 2*30) over a 1 gigabit/s link, how long will it take?". Welcome to every networking class in the 90s.
We should continue moving towards a world where 2*k prefixes have separate names and we use SI prefixes only for their precise base-10 meanings. The past is polluted but we hopefully have hundreds of years ahead of us to do things better.
That is a prescriptivist way of thinking about language, which is useful if you enjoy feeling righteous about correctness, but not so helpful for understanding how communication actually works. In reality-reality, "kilobyte" may mean either "1000 bytes" or "1024 bytes", depending on who is saying it, whom they are saying it to, and what they are saying it about.
You are free to intend only one meaning in your own communication, but you may sometimes find yourself being misunderstood: that, too, is reality.
It's not even really prescriptivist thinking… "Kilobyte" to mean both 1,000 B & 1,024 B is well-established usage, particularly dependent on context (with the context mostly being HDD manufacturers who want to inflate their drive sizes, and … the abomination that is the 1.44 MB diskette…). But a word can be dependent on context, even in prescriptivist settings.
E.g., M-W lists both, with even the 1,024 B definition being listed first. Wiktionary lists the 1,024 B definition, though it is tagged as "informal".
As a prescriptivist myself I would love if the world could standardize on kilo = 1000, kibi = 1024, but that'll likely take some time … and the introduction of the word to the wider public, who I do not think is generally aware of the binary prefixes, and some large companies deciding to use the term, which they likely won't do, since companies are apt to always trade for low-grade perpetual confusion over some short-term confusion during the switch.
Does anyone, other than HDD manufacturers who want to inflate their drive sizes, actually want a 1000-based kilobyte? What would such a unit be useful for? I suspect that a world which standardized on kibi = 1024 would be a world which abandoned the word "kilobyte" altogether.
> with the context mostly being HDD manufacturers who want to inflate their drive sizes
This is a myth. The first IBM harddrive was 5,000,000 characters in 1956 - before bytes were even common usage. Drives have always been base10, it's not a conspiracy.
Drives are base10, lines are base10, clocks are base10, pretty much everything but RAM is base10. Base2 is the exception, not the rule.
How can there be both a "usual meaning" and a "correct meaning" when you assert that there is only one meaning and "There's no possible discussion over this fact."
You can say that one meaning is more correct than the other, but that doesn't vanish the other meaning from existence.
When precision is required, you either use kibibytes or define your kilobytes explicitly. Otherwise there is a real risk that the other party does not share your understanding of what a kilobyte should mean in that context. Then the numbers you use have at most one significant figure.
That's funny. If I used the "correct" meaning when precision was required then I'd be wrong every time I need to use it. In computers, bytes are almost always measured in base-2 increments.
When dealing with microcontrollers and datasheets and talking to other designers, yes precision is required, and, e.g. 8KB means, unequivocally and unambiguously, 8192 bytes.
I kid good-naturedly. I'm always horrified at what autocorrect has done to my words after it's too late to edit or un-send them. I swear I write words goodly, for realtime!
The line between "literal" and "colloquial" becomes blurred when a word consisting of strongly-defined parts ("kilo") gets used in official, standardized contexts with a different meaning.
In fact, this is the only case I can think of where that has ever happened.
"colloquial" has no place in official contexts. I'll happily talk about kB and MB without considering the small difference between 1000 and 1024, but on a contract "kilo" will unequivocally mean 1000, unless explicitely defined as 1024 for the sake of that document.
Ah, if only I had a dollar for every time I've had to point someone to the a tool like the following when trying to explain the difference between how much "bandwidth" their server has per month (an IEC unit) vs how fast the server connection is (a SI unit): https://null.53bits.co.uk/uploads/programming/javascript/dat...
I'm suprised they didn't mention kibibyte. (Edit: they did) There are plenty of applications where power-of-2 alignment are useful or necessary. Not addressing that and just chastising everyone for using units wrong isn't particularly helpful. I guess we can just all switch to kibibytes, except the HDD manufacturers.
We can, but we won't. At least not any time soon. For the foreseeable future, kilobyte will remain an ambiguous term, and kibibyte will very often not be used when someone is referring to 1024 bytes.
The author doesn't go far enough into the problems with trying to convert information theory to SI Units.
SI units are attempting to fix standard measurements with perceived constants in nature. A meter(Distance) is the distance light travels in a vacuum, back and forth, within a certain amount of ossilations of a cesium atom(Time). This doesn't mean we tweak the meter to conform to observational results as we'd all be happier if light really was 300 000KM/s instead of ~299 792km/s.
Then there's the problem of not mixing different measurement units. SI was designed to conform all measurements to the same base 10 exponents (cm, m, km versus feet inches and yards) But the authors attempt to resolve this matter doesn't even conform to standardised SI units as we would expect them to.
What is a byte? Well, 8 bits, sometimes.
What is a kilobit? 1000 Bits
What is a kilobyte? 1000 Bytes, or 1024 Bytes.
Now we've already mixed units based on what a bit or a byte even is and the addition of the 8 multiplier in addition to the exponent of 1000 or 1024.
And if you think, hey, at least the bit is the least divisible unit of information, That's not even correct. If there Should* be a reformalisation of information units, you would agree that the amount of "0"'s is the least divisible unit of information. A kilo of zero's, would be 1000. A 'byte' would be defined as containing up to 256 zero's. A Megazero would contain up to a million zero's.
It wouldn't make any intuitive sense for anyone to count 0's, which would automatically convert your information back to base 10, but it does prove that the most sensible unit of information is already what we've had before, that is, you're not mixing bytes (powers of 2) with SI-defined units of 1000
<joke> How to tell a software engineer from a real one? A real engineer thinks that 1 kilobyte is 1000 bytes while software engineer believes that there are 1024 meters in a kilometer :-) </joke>
For all the people commenting as if the meaning of "kilo" was open to discussion... you are all from the United States of America, and you call your country "America", right?
It honestly sounds like how a diaper-wearing baby would mispronounce kilobyte.
"I will not sacrifice my dignity. We've made too many compromises already; too many retreats. They invade our space and we fall back. They assimilate entire worlds with awkward pronunciations. Not again. The line must be drawn here! This far, no further! And I will make them pay for what they've done to the kilobyte!"
I can go along with that, mostly. When you say "octet", some old-timer with an IBM 650 can't go whining that kids these days can't even read his 7-bit emails.
“A byte was described as consisting of any number of parallel bits from one to six. Thus a byte was assumed to have a length appropriate for the occasion. Its first use was in the context of the input-output equipment of the 1950s, which handled six bits at a time.”
"byte" doesn't even remotely resemble any decimal prefix, so it's okay. The problem is that prefixes "kilo", "mega", etc. are supposed to be decimal prefixes, but are used as binary. And what's worse, they aren't used consistently, sometimes they really mean decimal magnitudes, sometimes they don't.
It is good that the old ways have not been forgotten. We used to argue about tabs vs. spaces, GPL vs. BSD, Linux vs. BSD, FreeBSD vs. NetBSD, BSD 2 clause vs BSD 3 clause. It's important to complain about things pointlessly. Builds character.
Anyway, here's my contribution to help make everything worse. I think we should use Kylobyte, etc. when we don't care whether it's 1000 or 1024. KyB. See! Works great.
I like how the GNU coreutils seem to have done. They use real, 1024-byte kilobytes by default, but print only the abbreviation of the prefix so it's just 10K or 200M and people can pretend it stands for some other silly word if they want.
You can use `--si` for fake, 1000-byte kilobytes - trying it it seems weird that these are reported with a lowercase 'k' but 'M' and so on remain uppercase.
. . . it seems weird that these are reported with a lowercase 'k' but 'M' and so on remain uppercase.
For SI units, the abbreviations are defined, so a lowercase k for kilo and uppercase M for mega is correct. Lower case m is milli, c is centi, d is deci. Uppercase G is giga, T is tera and so on.
Not true. Several SI prefixes already overlap with units. m is both metre and milli-. T is tesla and tera-. c is a prefix of candela (cd) but also centi-. (G is gauss (cgs unit, not mks/SI) and giga-.)
I automatically assume that people that use KB=1000B want to sell me something (and provide less than promised), so should be aggressively ignored or removed from vicinities
KB is 1024 bytes, and don't you dare try stealing those 24 bytes from me
The entire reason "storage vendors prefer" 1000-based kilobytes is so that they could misrepresent and over-market their storage capacities, getting that 24-bytes per-kb of expectation-vs-reality profit.
It's the same reason—for pure marketing purposes—that screens are measured diagonally.
Not sure about that, SSDs historically have followed base-2 sizes (think of it as a legacy from their memory-based origins). What does happen in SSDs is that you have overprovisioned models that hide a few % of their total size, so instead of a 128GB SSD you get a 120GB one, with 8GB "hidden" from you that the SSD uses to handle wear leveling and garbage collection algorithms to keep it performing nicely for a longer period of time.
More recently you'd have, say, a 512GB SSD with 512GiB of flash so for usable space they're using the same base 10 units as hard disks. And yes, the difference in units happens to be enough overprovisioning for adequate performance.
Sounds like an urban legend. How likely is it that the optimal amount over-provisioning just so happens to match the gap between power-ten and power-two size conventions?
It doesn't, there's no singular optimal amount of over-provisioning. And that would make no sense, you'd have 28% over-provisioning for a 100/128GB drive, vs 6% over-provisioning for a 500/512GB drive, vs. 1.2% over-provisioning for a 1000/1024GB drive.
It's easy to find some that are marketed as 500GB and have 500x10^9 bytes [0]. But all the NVMe's that I can find that are marketed as 512GB have 512x10^9 bytes[1], neither 500x10^9 bytes nor 2^39 bytes. I cannot find any that are labeled "1TB" and actually have 1 Tebibyte. Even "960GB" enterprise SSD's are measured in base-10 gigabytes[2].
It's too late. Powers-of-two won. I'm the sort of person who uses "whom" in English, but even I acknowledge that using "KB" to mean 1,000, not 1,024, can only breed confusion. The purpose of language is to communicate. I'm all for pedantry when it's compatible with clarity, but we can't reconcile the two goals here.
No it didn't, look at your flash/hard drive labels. Also, there has been confusion since the beginning, and the core cause of confusion is refusing to use the common meaning of K, so insisting on that is just perpetuating said confusion
Those silly words only come up in discussions like this. I have never heard them uttered in real life. I don't think my experience is bizarre here - actual usage is what matters in my book.
To be honest, I think the power-ten SI people might have won the war against the power-two people if they'd just chosen a prefix that sounded slightly less ridiculous than "kibibyte".
What the hell is a "kibibyte"? Sounds like a brand of dog food.
I genuinely believe you're right. It comes across like "the people who are right can use the disputed word, and the people who are wrong can use this infantile one".
I don't know what the better alternative would have been, but this certainly wasn't it.
1. defined traditional suffixes and abbreviations to mean powers of two, not ten, aligning with most existing usages, but...
2. deprecated their use, especially in formal settings...
3. defined new spelled-out vocabulary for both pow10 and pow2 units, e.g. in English "two megabytes" becomes "two binary megabytes" or "two decimal megabytes", and...
4. defined new unambiguous abbreviations for both decimal and binary units, e.g. "5MB" (traditional) becomes "5bMB" (simplified, binary) or "5dMB" (simplified, decimal)
This way, most people most of the time could keep using the traditional units and be understood just fine, but in formal contexts in which precision is paramount, you'd have a standard way of spelling out exactly what you meant.
I'd have gone one step further too and stipulate that truth in advertising would require storage makers to use "5dMB" or "5 decimal megabytes" or whatever in advertising and specifications if that's what they meant. No cheating using traditional units.
(We could also split bits versus bytes using similar principles, e.g. "bi" vs "by".)
I mean consider UK, which still uses pounds, stone, and miles. In contexts where you'd use those units, writing "10KB" or "one megabyte" would be fine too.
Agreed. For the naysayers out there, consider these problems:
* You have 1 "MB" of RAM on a 1 MHz system bus which can transfer 1 byte per clock cycle. How many seconds does it take to read the entire memory?
* You have 128 "GB" of RAM and you have an empty 128 GB SSD. Can you successfully hibernate the computer system by storing all of RAM on the SSD?
* My camera shoots 6000×4000 pixels = exactly 24 megapixels. If you assume RGB24 color (3 bytes per pixel), how many MB of RAM or disk space does it take to store one raw bitmap image matrix without headers?
The SI definitions are correct: kilo- always means a thousand, mega- always means a million, et cetera. The computer industry abused these definitions because 1000 is close to 1024, creating endless confusion. It is a idiotic act of self-harm when one "megahertz" of clock speed is not the same mega- as one "megabyte" of RAM. IEC 60027 prefixes are correct: there is no ambiguity when kibi- (Ki) is defined as 1024, and it can coexist beside kilo- meaning 1000.
The whole point of the metric system is to create universal units whose meanings don't change depending on context. Having kilo- be overloaded (like method overloading) to mean 1000 and 1024 violates this principle.
If you want to wade in the bad old world of context-dependent units, look no further than traditional measures. International mile or nautical mile? Pound avoirdupois or Troy pound? Pound-force or pound-mass? US gallon or UK gallon? US shoe size for children, women, or men? Short ton or long ton? Did you know that just a few centuries ago, every town had a different definition of a foot and pound, making trade needlessly complicated and inviting open scams and frauds?
> The computer industry abused these definitions because 1000 is close to 1024, creating endless confusion.
They didn't abuse the definitions. It's simply the result of dealing with pins, wires, and bits. For your problems, for example, you won't ever have a system with 1 "MB" of RAM where that's 1,000,000 bytes. The 8086 processor had 20 address lines, 2^20, that's 1,048,576 bytes for 1MB. SI units make no sense for computers.
The only problem is unscrupulous hardware vendors using SI units on computers to sell you less capacity but advertise more.
Yes they did. Kilo- means 1000 in SI/metric. The computer industry decided, "Gee that looks awfully close to 1024. Let's sneakily make it mean 1024 in our context and sell our RAM that way".
> It's simply the result of dealing with pins, wires, and bits. For your problems, for example, you won't ever have a system with 1 "MB" of RAM where that's 1,000,000 bytes.
I'm not disputing that. I'm 100% on board with RAM being manufactured and operated in power-of-2 sizes. I have a problem with how these numbers are being marketed and communicated.
> SI units make no sense for computers.
Exactly! Therefore, use IEC 60027 prefixes like kibi-, because they are the ones that reflect the binary nature of computers. Only use SI if you genuinely respect SI definitions.
> Exactly! Therefore, use IEC 60027 prefixes like kibi-, because they are the ones that reflect the binary nature of computers. Only use SI if you genuinely respect SI definitions.
You have to sort of remember that these didn't exist at the time that "kilobyte" came around. The binary prefixes are — relatively speaking — very new.
I'm happy to say it isn't an SI unit. Kilo meaning 1000 makes no sense for computers, so lets just never use it to mean that.
> Therefore, use IEC 60027 prefixes like kibi-,
No. They're dumb. They sound stupid, they were decades too late, etc. This was a stupid plan. We can define Kilo as 1024 for computers -- we could have done that easily -- and just don't call them SI units if that makes people weird. This is how we all actually work. So rather than be pedantic about it lets make the language and units reflect their actual usage. Easy.
That's still wrong and you've solved nothing. 32 Gb = 32 000 000 000 bits = 4 000 000 000 bytes = 4 GB (real SI gigabytes).
If you think 32 Gb are binary gibibits, then you've disagreed with Ethernet (e.g. 2.5 Gb/s), Thunderbolt (e.g. 40 Gb/s), and other communication standards.
That's why I keep hammering on the same point: Creating context-dependent prefixes sows endless confusion. The only way to stop the confusion is to respect the real definitions.
I remember when they invented kibibytes and mibibytes and shaking my head and being like they have forever destroyed the meaning of words and things will be off by 2% forever. And is has been.
Metric prefixing should only be used with the unit bit. There is no confusion there. I mean, if you would equate a bit with a certain voltage threshold, you could even argue about fractional bits.
Approximating metric prefixing with kibi, Mibi, Gibi... is confusing because it doesn't make sense semantically. There is nothing base-10-ish about it.
Why don’t kilobyte continue to mean 1024 and introduce kilodebyte to mean 1000. Byte, to me implies a binary number system, and if you want to introduce a new nomenclature to reduce confusion, give the new one a new name and let the older of more prevalent one in its domain keep the old one…
Because kilo- already has a meaning. And both usages of kilobyte were (and are) in use. If we are going to fix the problem, we might as well fix it right.
Which universe do you hail from? Because nobody except pedants have relented to this demand from non-computer scientists to conform to a standardization that has nothing to do with them or the work they do.
The author decidedly has expert syndrome -- they deny both the history and rational behind memory units nomenclature. Memory measurements evolved utilizing binary organizational patterns used in computing architectures. While a proud French pedant might agree with the decimal normalization of memory units discussed, it aligns more closely to the metric system, and it may have benefits for laypeople, it fails to account for how memory is partitioned in historic and modern computing.
It’s not them denying it, it’s the LLM that generated this slop.
All they had to say was that the KiB et. al. were introduced in 1998, and the adoption has been slow.
And not “but a kilobyte can be 1000,” as if it’s an effort issue.
They are managed by different standards organizations. One doesn't like the other encroaching on its turf. "kilo" has only one official meaning as a base-10 scalar.
What are you talking about? The article literally fully explains the rationale, as well as the history. It's not "denying" anything. Seems entirely reasonable and balanced to me.
They are definitely denying the importance of 2-fold partitioning in computing architectures. VM_PAGE_SIZE is not defined with the value of '10000' for good reason (in many operating systems it is set to '16384').
That's why I said "usually acceptable depending on the context". In spoken language I also don't like the awkward and unusual pronunciation of "kibi". But I'll still prefer to write in KiB, especially if I document something.
Also If you open major Linux distro task managers, you'll be surprised to see that they often show in decimal units when "i" is missing from the prefix. Many utilities often avoid the confusing prefixes "KB", "MB"... and use "KiB", "MiB"...
No they're not? They very specifically address it.
Why do you keep insisting the author is denying something when the author clearly acknowledges every single thing you're complaining about?
A mile is exactly 1000 paces, or 4000 feet. You may disagree, but consider: the word mile come from latin for "one thousand". Therefore a mile must be 1000 of something, namely paces. I hope you find this argument convincing.
Webster’s dictionary defines a mile as …
And a megabyte is depending on the context precisely 1000x1000=1,000,000 or 1024x1024=1,048,576 bytes*, except when you're talking about the classic 3.5 inch floppy disks, where "1.44 MB" stands for 1440x1024 bytes, or about 1.47 true MB or 1.41 MiB.
* Yeah, I read the article. Regardless of the IEC's noble attempt, in all my years of working with people and computers I've never heard anyone actually pronounce MiB (or write it out in full) as "mebibyte".
Well the 1.44 MB, was called that because it was 1440 KB, twice the capacity of the 720k floppy, and 4x the 360k floppy. It made perfect sense to me at that time.
It may "make sense" but that's actually a false equivalence. The raw disk space for a 3.5" high-density floppy disk for IBM PCs is 512 bytes per sector * 18 sectors per track * 80 tracks per side * 2 sides = 1,474,560 bytes. It is 1.47 MB or 1.40 MiB neither of which is 1440 KB or KiB. The 1440 number comes from Microsoft's FAT12 filesystem. That was the space that's left for files outside the allocation table.
Sectors per track or tracks per side is subject to change. Moreover a different filesystem may have non-linear growth of the MFT/superblock that'll have a different overhead.
https://en.wikipedia.org/wiki/List_of_floppy_disk_formats
I worked with networked attached storage systems at pib scale several years ago and we referred to things in gib/tib because it was significant when referring to the size of systems and we needed to be precise.
That being said, I think the difference between mib and mb is niche for most people
> I've never heard
It doesn't matter. "kilo" means 1000. People are free to use it wrong if they wish.
All words are made up. They weren’t handed down from a deity, they were made up by humans to communicate ideas to other humans.
“Kilo” can mean what we want in different contexts and it’s really no more or less correct as long as both parties understand and are consistent in their usage to each other.
I find it concerning that kilo can mean both 10^3 and 2^10 depending on context. And that the context is not if you're speaking about computery stuff, but which program you use has almost certainly lead to avoidable bugs.
[delayed]
That latter part is only true since marketing people decided they knew better about computer related things than computer people.
It's also stupid because it's rare than anyone outside of programming even needs to care exactly how many bytes something else. At the scales that each of kilobyte, megabyte, gigabyte, terabyte etc are used, the smaller values are pretty much insignificant details.
If you ask for a kilogram of rice, then you probably care more about that 1kg of rice is the same as the last 1kg of rice you got, you probably wouldn't even care how many grams that is. Similarly, if you order 1 ton of rice, you do care exactly how many grams it is, or do you just care that this 1 ton is the same as that 1 ton?
This whole stupidity started because hard disk manufacturers wanted to make their drives sound bigger than they actually were. At the time, everybody buying hard disks knew about this deception and just put up with it. We'd buy their 2GB drive and think to ourselves, "OK so we have 1.86 real GB". And that was the end of it.
Can you just imagine if manufacturers started advertising computers as having 34.3GB of RAM? Everybody would know it was nonsense and call it 32GB anyway.
>> It doesn't matter. "kilo" means 1000. People are free to use it wrong if they wish.
> All words are made up.
Yes, and the made up words of kilo and kibi were given specific definitions by the people who made them up:
* https://en.wikipedia.org/wiki/Metric_prefix
* https://en.wikipedia.org/wiki/Binary_prefix
> […] as long as both parties understand and are consistent in their usage to each other.
And if they don't? What happens then?
Perhaps it would be easier to use the words definitions as they are set up in standards and regulations so context is less of an issue.
* https://xkcd.com/1860/
> Yes, and the made up words of kilo and kibi were given specific definitions by the people who made them up
Kilo was generally understood to mean one thousand long before it was adopted by a standards committee. I know the French love to try and prescribe the use of language, but in most of the world words just mean what people generally understand them to mean; and that meaning can change.
> Yes, and the made up words of kilo and kibi were given specific definitions by the people who made them up
Good for them. People make up their own definitions for words all the time. Some of those people even try to get others to adopt their definition. Very few are ever successful. Because language is about communicating shared meaning. And there is a great deal of cultural inertia behind the kilo = 2^10 definition in computer science and adjacent fields.
I don't think that the xkcd is relevant here, because I'm arguing that both parties know what the other is talking about. I haven't implicitly changed the definition because most people assume that kilobyte is 1024 bytes. Yeah, sure, it's "wrong" in some sense, but language is about communicating ideas between two people; if the communication is successful than the word is "correct".
If Bob says "kilobyte" to Alice, and Bob means 5432 bytes, and Alice perceives him to mean 5432 bytes, then in that context, "kilobyte" means 5432 bytes.
[delayed]
What are the odds of Charlie meeting Bob and Alice?
Is charlie a marketing exec?
> classic 3.5 inch floppy disks
90 mm floppy disks. https://jdebp.uk/FGA/floppy-discs-are-90mm-not-3-and-a-half-...
Which I have taken to calling 1440 KiB – accurate and pretty recognizable at the same time.
I had a computer architecture prof (a reasonably accomplished one, too) who thought that all CS units should be binary, e.g. Gigabit Ethernet should be 931Mbit/s, not 1000MBit/s.
I disagreed strongly - I think X-per-second should be decimal, to correspond to Hertz. But for quantity, binary seems better. (modern CS papers tend to use MiB, GiB etc. as abbreviations for the binary units)
Fun fact - for a long time consumer SSDs had roughly 7.37% over-provisioning, because that's what you get when you put X GB (binary) of raw flash into a box, and advertise it as X GB (decimal) of usable storage. (probably a bit less, as a few blocks of the X binary GB of flash would probably be DOA) With TLC, QLC, and SLC-mode caching in modern drives the numbers aren't as simple anymore, though.
This is the bit (sic) that drives me nuts.
RAM had binary sizing for perfectly practical reasons. Nothing else did (until SSDs inherited RAM's architecture).
We apply it to all the wrong things mostly because the first home computers had nothing but RAM, so binary sizing was the only explanation that was ever needed. And 50 years later we're sticking to that story.
RAM having binary sizing is a perfectly good reason for hard drives having binary sized sectors (more efficient swap, memory maps, etc), which in turn justifies all of hard disks being sized in binary.
Nope. The first home computers like the C64 had RAM and sectors on disc, which in case of the C64 means 256 bytes. And there it is again, the smaller base of 1024.
Just later, some marketing assholes thought they could better sell their hard drives when they lie about the size and weasel out of legal issues with redefining the units.
There's a good reason that gigabit ethernet is 1000MBit/s and that's because it was defined in decimal from the start. We had 1MBit/s, then 10MBit/s, then 100MBit/s then 1000MBit/s and now 10Gbit/s.
Interestingly, from 10GBit/s, we now also have binary divisions, so 5GBit/s and 2.5GBit/s.
Even at slower speeds, these were traditionally always decimal based - we call it 50bps, 100bps, 150bps, 300bps, 1200bps, 2400bps, 9600bps, 19200bps and then we had the odd one out - 56k (actually 57600bps) where the k means 1024 (approximately), and the first and last common speed to use base 2 kilo. Once you get into MBps it's back to decimal.
This has nothing to do with the 1024, it has todo with the 1200 and the multiples of it and the 14k and 28k modems where everyone just cut off the last some hundred bytes because you never reached that speed anyway.
Wirespeeds and bitrate and baud and all that stuff is vastly confusing when you start looking into it - because it's hard to even define what a "bit on the wire" is when everything has to be encoded in such a way that it can be decoded (specialized protocols can go FASTER than normal ones on the same wire and the same mechanism if they can guarantee certain things - like never having four zero bits in a row).
I can see a precision argument for binary represented frequencies. A systems programmer would value this. A musician would not.
musicians use numbering systems that are actually far more confused than anything discussed here. how many notes in an OCTave? "do re mi fa so la ti do" is eight, but that last do is part of the next octave, so an OCTave is 7 notes. (if we count transitions, same thing, starting at the first zero do, re is 1, ... again 7.
the same and even more confusion is engendered when talking about "fifths" etc.
The 7 note scale you suggest (do re mi fa so la ti do) is comprised of different intervals (2 2 1 2 2 2 1) in the 12-fold equal tempered scale. There are infinite ways of exploring an octave in music, but unfortunately listener demand for such exploration is near infinitesimal.
don't you mean 11-fold? ... oh wait, they aren't even consistent
They sum to 12
actually they multiply, 12th root of 2, to the 12th
You can blame the Romans for that, as they practiced inclusive counting. Their market days occurring once every 8 days were called nundinae, because the next market day was the ninth day from the previous one. (And by the same logic, Jesus rose from the dead on the third day.)
Musicians often use equal temperament, so they have their own numerical crimes to answer for.
Touché, appropriate to describe near compulsory equal temperament (ala MIDI) as a crime.
An even bigger problem is that networks are measured in bits while RAM and storage are in bytes. I'm sure this leads to plenty of confusion when people see a 120 meg download on their 1 gig network.
(The old excuse was that networks are serial but they haven't been serial for decades.)
Whenever this discussion comes up I liked to point out that even in the computer industry, prefixes like kilo/mega/etc more often mean a power of 10 than a power of 2:
I gave some examples in my post https://blog.zorinaq.com/decimal-prefixes-are-more-common-th...
Nice page, and nice link to Colin Percival's page too! Let me toss you one example: CDs are marketed in mebibytes. A "650 MB" burnable CD is actually 650 MiB ≈ 682 MB, and likewise for "700 MB" being actually 700 MiB ≈ 734 MB. DVD and BD do use metric prefixes correctly, like you pointed out. Back in the day, I archived my data on CD/DVD/BD, and I planned out my disc burns to have only about 1 to 10 MB of wasted space, so I had to be very aware of the true definition and exactly how much capacity was available for me to use.
They almost always mean power of 10, unless you're discussing RAM, RAM addressing, or RAM pages. (or flash, which has inherited most of the same for most of the same reasons)
> The only few places where binary prefixes are used are to refer to RAM capacity and file sizes, whereas decimal prefixes apply to all other areas and all units (not "only bitrates"): storage capacity, clock frequency, stream bandwidth, baud, pixel numbers, data throughput, processing power
Storage capacity also uses binary prefixes. The distinction here isn't that file sizes are reported in binary numbers and storage capacity is reported in decimal numbers. It's that software uses binary numbers and hard drive manufacturers use decimal numbers. You don't see df reporting files in binary units and capacities in decimal units.
Of that large list of measurements, only bandwidth is measured in bytes, making the argument mostly an exercise in sophistry. You can't convince anyone that KB means 1000 bytes by arguing that kHz means 1000 Hz.
I'm sticking with power-of-2 sizes. Invent a new word for decimal, metric units where appropriate. I proposed[0] "kitribytes", "metribytes", "gitribytes", etc. Just because "kilo" has a meaning in one context doesn't mean we're stuck with it in others. It's not as though the ancient Greeks originally meant "kilo" to mean "exactly 1,000". "Giga" just meant "giant". "Tera" is just "monster". SI doesn't have sole ownership for words meaning "much bigger than we can possibly count at a glance".
Donald Knuth himself said[1]:
> The members of those committees deserve credit for raising an important issue, but when I heard their proposal it seemed dead on arrival --- who would voluntarily want to use MiB for a maybe-byte?! So I came up with the suggestion above, and mentioned it on page 94 of my Introduction to MMIX. Now to my astonishment, I learn that the committee proposals have actually become an international standard. Still, I am extremely reluctant to adopt such funny-sounding terms; Jeffrey Harrow says "we're going to have to learn to love (and pronounce)" the new coinages, but he seems to assume that standards are automatically adopted just because they are there.
If Gordon Bell and Gene Amdahl used binary sizes -- and they did -- and Knuth thinks the new terms from the pre-existing units sound funny -- and they do -- then I feel like I'm in good company on this one.
0: https://honeypot.net/2017/06/11/introducing-metric-quantity....
1: https://www-cs-faculty.stanford.edu/~knuth/news99.html
Knuth is not in favour of using kilo/mega/etc with power-of-2 meanings:
> I'm a big fan of binary numbers, but I have to admit that this convention flouts the widely accepted international standards for scientific prefixes.
He also calls it “an important issue” and had written “1000 MB = 1 gigabyte (GB), 1000 GB = 1 terabyte (TB), 1000 TB = 1 petabyte (PB), 1000 PB = 1 exabyte (EB), 1000 EB = 1 zettabyte (ZB), 1000 ZB = 1 yottabyte (YB)” in his MMIX book even before the new binary prefixes became an international standard.
He is merely complaining that the new names for the binary prefixes sound funny (and has his own proposal like “large megabyte” and notation MMB etc), but he's still using the kilo/mega/etc prefixes with decimal meanings.
> Invent a new word for decimal, metric units where appropriate.
No, they already did the opposite with KiB, MiB.
Because most metric decimal units are used for non-computing things. Kilometers, etc. Are you seriously proposing that kilometers should be renamed kitrimeters because you think computing prefixes should take priority over every other domain of science and life?
Do you often convert between inherently binary units like RAM sizes and more appropriately decimal units like distances?
It would be annoying of one frequently found themselves calculating gigabytes per hectare. I don't think I've ever done that. The closest I've seen is measure magnetic tape density where you get weird units like "characters per inch", where neither "character" nor "inch" are the common units for their respective metrics.
I have no idea what that is supposed to have to do with anything.
It means that is fine for Kilo to mean 1024 in the context of computers and 1000 in the context of distances, because you're never going to be in a situation where that is ambiguous.
Except it's not because it's constantly ambiguous in computing.
E.g. Macs measure file sizes in powers of 10 and call them KB, MB, GB. Windows measures file sizes in powers of 2 and calls them KB, MB, GB instead of KiB, MiB, GiB. Advertised hard drives come in powers of 10. Advertised memory chips come in powers of 2.
When you've got a large amount of data or are allocating an amount of space, are you measuring its size in memory or on disk? On a Mac or on Windows?
The mistake was using the "Kibi" prefix. "Kibibyte" just sounds a bit silly when said out loud.
"Giga" was considered to sound silly until it became common and we no longer care. "Yotta" sounds silly (to me) now.
"Tera" always sounded cool though.
Surely you mean Gibi ;)
Yes, 2**10 times this, yes.
Call me calcitrant, reactionary, or whatever, but I will not say kibibyte out loud. It's a dumb word and I'm not using it. It was a horrible choice.
They should call their stupid SI power-of-10 units kisibyte instead.
When I read "KiB" I say "kib" and it's fine. Similar for GiB, TiB, PiB.
"I bought a two tib SSD."
"I just want to serve five pibs."
>"I bought a two tib SSD."
no you didn't, that doesn't exist, you bought 2 trillion bytes, 99 billion bytes short
Actually, it sounds very serious and appropriate.
Studio Kibi
"mebi" and "gibi" aren't any better, last one in particular if you say it as "jibby-bytes"
Does it really matter if it sounds silly?
Considering it meant people didn't use it, yes.
> Why does 1000 still make more sense?
The author doesn’t actually answer their question, unless I missed something?
They go on to make a few more observations, and say finally only that the current different definitions are sometimes confusing, to non experts.
I don’t see much of an argument here for changing anything. Some non experts experience minor confusion about two things that are different, did I miss something bigger in this?
Because it would be literally correct. Kilo means 1000, not 1024.
It would be "literally correct" for you but obviously incorrect to everybody else who has the understanding that a kilobyte = 1024 bytes
"kilo" means what people take it to mean in any particular context. In computing, it is overwhelmingly power of two even today, and if you don't use it in this manner you have to clarify to be understood properly.
Was reading this and thought the same thing.
To clear up any confusion, let's compromise at a 1012-byte kilobyte.
I like the binch better, it's like an inch, but its 25.6 mm instead.
>Why do we often say 1 kilobyte = 1024 bytes?
Because Windows, and only Windows, shows it this way. It is official and documented: https://devblogs.microsoft.com/oldnewthing/20090611-00/?p=17...
> Explorer is just following existing practice. Everybody (to within experimental error) refers to 1024 bytes as a kilobyte, not a kibibyte. If Explorer were to switch to the term kibibyte, it would merely be showing users information in a form they cannot understand, and for what purpose? So you can feel superior because you know what that term means and other people don’t.
Raymond Chen's blog isn't exactly official documentation, even if it's frequently better than the documentation.
I know the only other software with this kind of error: https://github.com/lsd-rs/lsd/issues/807
Windows also uses KB as measure unit which does not make sense (it's either kB or KiB)
The meaning of kilo, mega, giga, tera, etc. are unambiguous: SI prefixes defined as powers of 10, not 2. 1 TB is 10*12 bytes, not 2*40 bytes.
The misuse of those prefixes as powers of 1024, while useful as shorthand for computer memory where binary addressing means, is still exactly that: a misuse of SI prefixes.
There's now a separate set of base-2 prefixes to solve this, and people need to update their language accordingly.
Just because an official body gives a single definition doesn't mean it's unambiguous. Real communication isn't bound by official bodies. When I say my computer has 16GB of RAM, that does not mean exactly 16 billion bytes.
I need to update my language accordingly? No thanks. I'll keep saying what I say and nothing will happen.
Final edit:
This ambiguity is documented at least back to 1984, by IBM, the pre-eminent computer company of the time.
In 1972 IBM started selling the IBM 3333 magnetic disk drive. This product catalog [0] from 1979 shows them marketing the corresponding disks as "100 million bytes" or "200 million bytes" (3336 mdl 1 and 3336 mdl 11, respectively). By 1984, those same disks were marketed in the "IBM Input/Output Device Summary"[1] (which was intended for a customer audience) as "100MB" and "200MB"
0: (PDF page 281) "IBM 3330 DISK STORAGE" http://electronicsandbooks.com/edt/manual/Hardware/I/IBM%20w...
1: (PDF page 38, labeled page 2-7, Fig 2-4) http://electronicsandbooks.com/edt/manual/Hardware/I/IBM%20w...
Also, hats off to http://electronicsandbooks.com/ for keeping such incredible records available for the internet to browse.
-------
Edit: The below is wrong. Older experience has corrected me - there has always been ambiguity (perhaps bifurcated between CPU/OS and storage domains). "And that with such great confidence!", indeed.
-------
The article presents wishful thinking. The wish is for "kilobyte" to have one meaning. For the majority of its existence, it had only one meaning - 1024 bytes. Now it has an ambiguous meaning. People wish for an unambiguous term for 1000 bits, however that word does not exist. People also might wish that others use kibibyte any time they reference 1024 bytes, but that is also wishful thinking.
The author's wishful thinking is falsely presented as fact.
I think kilobyte was the wrong word to ever use for 1024 bytes, and I'd love to go back in time to tell computer scientists that they needed to invent a new prefix to mean "1,024" / "2^10" of something, which kilo- never meant before kilobit / kilobyte were invented. Kibi- is fine, the phonetics sound slightly silly to native English speakers, but the 'bi' indicates binary and I think that's reasonable.
I'm just not going to fool myself with wishful thinking. If, in arrogance or self-righteousness, one simply assumes that every time they see "kilobyte" it means 1,000 bytes - then they will make many, many failures. We will always have to take care to verify whether "kilobyte" means 1,000 or 1,024 bytes before implementing something which relies on that for correctness.
You've got it exactly the wrong way around. And that with such great confidence!
There was always a confusion about whether a kilobyte was 1000 or 1024 bytes. Early diskettes always used 1000, only when the 8 bit home computer era started was the 1024 convention firmly established.
Before that it made no sense to talk about kilo as 1024. Earlier computers measured space in records and words, and I guess you can see how in 1960, no one would use kilo to mean 1024 for a 13 bit computer with 40 byte records. A kiloword was, naturally, 1000 words, so why would a kilobyte be 1024?
1024 bearing near ubiquitous was only the case in the 90s or so - except for drive manufacturing and signal processing. Binary prefixes didn't invent the confusion, they were a partial solution. As you point out, while it's possible to clearly indicate binary prefixes, we have no unambiguous notation for decimal bytes.
> Early diskettes always used 1000
Even worse, the 3.5" HD floppy disk format used a confusing combination of the two. Its true capacity (when formatted as FAT12) is 1,474,560 bytes. Divide that by 1024 and you get 1440KB; divide that by 1000 and you get the oft-quoted (and often printed on the disk itself) "1.44MB", which is inaccurate no matter how you look at it.
I'm not seeing evidence for a 1970s 1000-byte kilobyte. Wikipedia's floppy disk page mentions the IBM Diskette 1 at 242944 bytes (a multiple of 256), and then 5¼-inch disks at 368640 bytes and 1228800 bytes, both multiples of 1024. These are sector sizes. Nobody had a 1000-byte sector, I'll assert.
The wiki page agrees with parent, "The double-sided, high-density 1.44 MB (actually 1440 KiB = 1.41 MiB or 1.47 MB) disk drive, which would become the most popular, first shipped in 1986"
To make things even more confusing, the high-density floppy introduced on the Amiga 3000 stored 1760 KiB
At least there it stored exactly 3,520 512-byte sectors, or 1,760 KB. They didn't describe them as 1.76MB floppies.
Human history is full of cases where silly mistakes became precedent. HTTP "referal" is just another example.
I wonder if there's a wikipedia article listing these...
It's "referer" in the HTTP standard, but "referrer" when correctly spelled in English. https://en.wikipedia.org/wiki/HTTP_referer
it's, way older in than the 1990's! In computering, "K" always meant 1024 at least from 1970's.
Example: in 1972, DEC PDP 11/40 handbook [0] said on first page: "16-bit word (two 8-bit bytes), direct addressing of 32K 16-bit words or 64K 8-bit bytes (K = 1024)". Same with Intel - in 1977 [1], they proudly said "Static 1K RAMs" on the first page.
[0] https://pdos.csail.mit.edu/6.828/2005/readings/pdp11-40.pdf
[1] https://deramp.com/downloads/mfe_archive/050-Component%20Spe...
It was exactly this - and nobody cared until the disks (the only thing that used decimal K) started getting so big that it was noticeable. With a 64K system you're talking 1,536 "extra" bytes of memory - or 1,536 bytes of memory lost when transferring to disk.
But once hard drives started hitting about a gigabyte was when everyone started noticing and howling.
It was earlier than the 90s, and came with popular 8-bit CPUs in the 80s. The Z-80 microprocessor could address 64kb (which was 65,536 bytes) on its 16-bit address bus.
Similarly, the 4104 chip was a "4kb x 1 bit" RAM chip and stored 4096 bits. You'd see this in the whole 41xx series, and beyond.
> The Z-80 microprocessor could address 64kb (which was 65,536 bytes) on its 16-bit address bus.
I was going to say that what it could address and what they called what it could address is an important distinction, but found this fun ad from 1976[1].
"16K Bytes of RAM Memory, expandable to 60K Bytes", "4K Bytes of ROM/RAM Monitor software", seems pretty unambiguous that you're correct.
Interestingly wikipedia at least implies the IBM System 360 popularized the base-2 prefixes[2], citing their 1964 documentation, but I can't find any use of it in there for the main core storage docs they cite[3]. Amusingly the only use of "kb" I can find in the pdf is for data rate off magnetic tape, which is explicitly defined as "kb = thousands of bytes per second", and the only reference to "kilo-" is for "kilobaud", which would have again been base-10. If we give them the benefit of the doubt on this, presumably it was from later System 360 publications where they would have had enough storage to need prefixes to describe it.
[1] https://commons.wikimedia.org/wiki/File:Zilog_Z-80_Microproc...
[2] https://en.wikipedia.org/wiki/Byte#Units_based_on_powers_of_...
[3] http://www.bitsavers.org/pdf/ibm/360/systemSummary/A22-6810-...
Even then it was not universal. For example, that Apple I ad that got posted a few days ago mentioned that "the system is expandable to 65K". https://upload.wikimedia.org/wikipedia/commons/4/48/Apple_1_...
Someone here the other day said that it could accept 64KB of RAM plus 1KB of ROM, for 65KB total memory.
I don't know if that's correct, but at least it'd explain the mismatch.
Seems like a typo given that the ad contains many mentions of K (8K, 32K) and they're all of the 1024 variety.
If you're using base 10, you can get "8K" and "32K" by dividing by 10 and rounding down. The 1024/1000 distinction only becomes significant at 65536.
Still the advertisement is filled with details like the number of chips, the number of pins, etc. If you're dealing with chips and pins, it's always going to base-2.
only when the 8 bit home computer era started was the 1024 convention firmly established.
That's the microcomputer era that has defined the vast majority of our relationship with computers.
IMO, having lived through this era, the only people pushing 1,000 byte kilobytes were storage manufacturers, because it allows them to bump their numbers up.
https://www.latimes.com/archives/la-xpm-2007-nov-03-fi-seaga...
> 1024 bearing near ubiquitous was only the case in the 90s or so
More like late 60s. In fact, in the 70s and 80s, I remember the storage vendors being excoriated for "lying" by following the SI standard.
There were two proposals to fix things in the late 60s, by Donald Morrison and Donald Knuth. Neither were accepted.
Another article suggesting we just roll over and accept the decimal versions is here:
https://cacm.acm.org/opinion/si-and-binary-prefixes-clearing...
This article helpfully explains that decimal KB has been "standard" since the very late 90s.
But when such an august personality as Donald Knuth declares the proposal DOA, I have no heartburn using binary KB.
https://www-cs-faculty.stanford.edu/~knuth/news99.html
Good lord, arrogance and self-righteousness? You're blowing the article out of proportion. They don't say anything non-factual or unreasonable - why inject hostility where none is called for?
In fact, they practically say the same exact thing you have said: In a nutshell, base-10 prefixes were used for base-2 numbers, and now it's hard to undo that standard in practice. They didn't say anything about making assumptions. The only difference is that that the author wants to keep trying, and you don't think it's possible? Which is perfectly fine. It's just not as dramatic as your tone implies.
I'm not calling the author arrogant or self-righteous. I stated that if a hypothetical person simply assumes that every "kilobyte" they come across is 1,000 bytes, that they are doomed to frequent failures. I implied that for someone to hypothetically adhere to that internal dogma even in the face of impending failures, the primary reasons would be either arrogance or self-righteousness.
I don't read any drama or hostility, just a discussion about names. OP says that kilobyte means one thing, the commenter says that it means two things and just saying it doesn't can't make that true. I agree, after all, we don't get to choose the names for things that we would like.
> The article presents wishful thinking. The wish is for "kilobyte" to have one meaning. For the majority of its existence, it had only one meaning - 1024 bytes. Now it has an ambiguous meaning. People wish for an unambiguous term for 1000 bits, however that word does not exist. People also might wish that others use kibibyte any time they reference 1024 bytes, but that is also wishful thinking.
> The author's wishful thinking is falsely presented as fact.
There's good reason why the meanings of SI prefixes aren't set by convention or by common usage or by immemorial tradition, but by the SI. We had several thousand years of setting weights and measures by local and trade tradition and it was a nightmare, which is how we ended up with the SI. It's not a good show for computing to come along and immediately recreate the long and short ton.
> setting weights and measures by local and trade tradition and it was a nightmare
Adding to your point, it is human nature to create industry- or context-specific units and refuse to play with others.
In the non-metric world, I see examples like: Paper publishing uses points (1/72 inch), metal machinists use thousands of an inch, woodworkers use feet and inches and binary fractions, land surveyors use decimal feet (unusual!), waist circumference is in inches, body height is in feet and inches, but you buy fabric by the yard, airplane altitudes are in hundreds to tens of thousands of feet instead of decimal miles. Crude oil is traded in barrels but gasoline is dispensed in gallons. Everyone thinks their usage of units and numbers is intuitive and optimal, and everyone refuses to change.
In the metric(ish) world, I still see many tensions. The micron is a common alternate name for the micrometre, yet why don't we have a millin or nanon or picon? The solution is to eliminate the micron. I've seen the angstrom (0.1 nm) in spectroscopy and in the discussion of CPU transistor sizes, yet it diverts attention away from the picometre. The bar (100 kPa) is popular in talking about things like tire pressure because it's nearly 1 atmosphere. The mmHg is a unit of pressure that sounds metric but is not; the correct unit is pascal. No one in astronomy uses mega/giga/tera/peta/etc.-metres; instead they use AU and parsec and (thousand, million, billion) light-years. Particle physics use eV/keV/MeV instead of some units around the picojoule.
Having a grab bag of units and domains that don't talk to each other is indeed the natural state of things. To put your foot down and say no, your industry does not get its own special snowflake unit, stop that nonsense and use the standardized unit - that takes real effort to achieve.
The SI should just have set kilobyte to 1024 in acquiescence to the established standard, instead of being defensive about keeping a strict meaning of the prefix.
It goes back way further than that. The first IBM harddrive was the IBM 350 for the IBM 305 RAMDAC. It was 5 million characters. Not bytes, bytes weren't "a thing" yet. 5,000,000 characters. The very first harddrive was base-10.
Here's my theory. In the beginning, everything was base10. Because humans.
Binary addressing made sense for RAM. Especially since it makes decoding address lines into chip selects (or slabs of core, or whatever) a piece of cake, having chips be a round number in binary made life easier for everyone.
Then early DOS systems (CP/M comes to mind particularly) mapped disk sectors to RAM regions, so to enable this shortcut, disk sectors became RAM-shaped. The 512-byte sector was born. File sizes can be written in bytes, but what actually matters is how many sectors they take up. So file sizing inherited this shortcut.
But these shortcuts never affected "real computers", only the hamstrung crap people were running at home.
So today we have multiple ecosystems. Some born out of real computers, some with a heavy DOS inheritance. Some of us were taught DOS's limitations as truth, and some of us weren't.
RAMAC, not RAMDAC: https://en.wikipedia.org/wiki/History_of_IBM_magnetic_disk_d...
However it doesn't seem to be divided into sectors at all, more like each track is like a loop of magnetic tape. In that context it makes a bit more sense to use decimal units, measuring in bits per second like for serial comms.
Or maybe there were some extra characters used for ECC? 5 million / 100 / 100 = 500 characters per track, leaves 72 bits over for that purpose if the actual size was 512.
First floppy disks - also from IBM - had 128-byte sectors. IIRC, it was chosen because it was the smallest power of two that could store an 80-column line of text (made standard by IBM punched cards).
Disk controllers need to know how many bytes to read for each sector, and the easiest way to do this is by detecting overflow of an n-bit counter. Comparing with 80 or 100 would take more circuitry.
Almost all computers have used power-of-2 sized sectors. The alternative would involve wasted bits (e.g. you can't store as much information in 256 1000-byte units as 256 1024-byte units, so you lose address space) or have to write multiplies and divides and modulos in filesystem code running on machines that don't have opcodes for any of those.
You can get away with those on machines with 64 bit address spaces and TFLOPs of math capacity. You can't on anything older or smaller.
At least it's not a total bizarro unit like "Floppy Disk Megabyte", equal to 1024000 bytes.
Are you talking about imperial or metric kilobyte?
> Edit: I'm wrong.
You need character to admit that. I bow to you.
> Edit: I'm wrong. Older experience has corrected me - there has always been ambiguity "And that with such great confidence!", indeed.
Kudos for getting back. (and closing the tap of "you are wrong" comments :))
At this point I just wish 2^10 didn't end up so close to 1000.
To avoid confusion, I always use "kilobyte" to refer to exactly 512 bytes.
Not to be confused with a kilonibble, which is 500 bytes.
People were using metric words for binary numbers since at least the late 1950s: https://en.wikipedia.org/wiki/Timeline_of_binary_prefixes#19...
Which doesn't make it more correct, of course, even through I strongly believe believe that it is (where appropriate for things like memory sizes). Just saying, it goes much further back than 1984.
And networking - we've almost always used standard SI prefixes for, e.g., bandwidth. 1 gigabit per second == 1 * 10^9.
Which makes it really @#ing annoying when you have things like "I want to transmit 8 gigabytes (meaning gibibytes, 2*30) over a 1 gigabit/s link, how long will it take?". Welcome to every networking class in the 90s.
We should continue moving towards a world where 2*k prefixes have separate names and we use SI prefixes only for their precise base-10 meanings. The past is polluted but we hopefully have hundreds of years ahead of us to do things better.
> The wish is for "kilobyte" to have one meaning.
Which is the reality. "kilobyte" means "1000 bytes". There's no possible discussion over this fact.
Many people have been using it wrong for decades, but its literal value did not change.
That is a prescriptivist way of thinking about language, which is useful if you enjoy feeling righteous about correctness, but not so helpful for understanding how communication actually works. In reality-reality, "kilobyte" may mean either "1000 bytes" or "1024 bytes", depending on who is saying it, whom they are saying it to, and what they are saying it about.
You are free to intend only one meaning in your own communication, but you may sometimes find yourself being misunderstood: that, too, is reality.
It's not even really prescriptivist thinking… "Kilobyte" to mean both 1,000 B & 1,024 B is well-established usage, particularly dependent on context (with the context mostly being HDD manufacturers who want to inflate their drive sizes, and … the abomination that is the 1.44 MB diskette…). But a word can be dependent on context, even in prescriptivist settings.
E.g., M-W lists both, with even the 1,024 B definition being listed first. Wiktionary lists the 1,024 B definition, though it is tagged as "informal".
As a prescriptivist myself I would love if the world could standardize on kilo = 1000, kibi = 1024, but that'll likely take some time … and the introduction of the word to the wider public, who I do not think is generally aware of the binary prefixes, and some large companies deciding to use the term, which they likely won't do, since companies are apt to always trade for low-grade perpetual confusion over some short-term confusion during the switch.
Does anyone, other than HDD manufacturers who want to inflate their drive sizes, actually want a 1000-based kilobyte? What would such a unit be useful for? I suspect that a world which standardized on kibi = 1024 would be a world which abandoned the word "kilobyte" altogether.
> with the context mostly being HDD manufacturers who want to inflate their drive sizes
This is a myth. The first IBM harddrive was 5,000,000 characters in 1956 - before bytes were even common usage. Drives have always been base10, it's not a conspiracy.
Drives are base10, lines are base10, clocks are base10, pretty much everything but RAM is base10. Base2 is the exception, not the rule.
I understand the usual meaning, but I use the correct meaning when precision is required.
How can there be both a "usual meaning" and a "correct meaning" when you assert that there is only one meaning and "There's no possible discussion over this fact."
You can say that one meaning is more correct than the other, but that doesn't vanish the other meaning from existence.
When precision is required, you either use kibibytes or define your kilobytes explicitly. Otherwise there is a real risk that the other party does not share your understanding of what a kilobyte should mean in that context. Then the numbers you use have at most one significant figure.
The correct meaning has always been 1024 bytes where I’m from. Then I worked with more people like you.
Now, it depends.
In computers, "kilobyte" has a context dependent meaning. It has been thus for decades. It does not only mean 1000 bytes.
I understand the usual meaning, but I use the correct meaning when precision is required.
That's funny. If I used the "correct" meaning when precision was required then I'd be wrong every time I need to use it. In computers, bytes are almost always measured in base-2 increments.
When dealing with microcontrollers and datasheets and talking to other designers, yes precision is required, and, e.g. 8KB means, unequivocally and unambiguously, 8192 bytes.
Ummm, should we tell him?
That I can't type worth shit?
Yeah, I already knew that, lol.
But thanks for bringing it to my attention. :-)
I kid good-naturedly. I'm always horrified at what autocorrect has done to my words after it's too late to edit or un-send them. I swear I write words goodly, for realtime!
The line between "literal" and "colloquial" becomes blurred when a word consisting of strongly-defined parts ("kilo") gets used in official, standardized contexts with a different meaning.
In fact, this is the only case I can think of where that has ever happened.
"colloquial" has no place in official contexts. I'll happily talk about kB and MB without considering the small difference between 1000 and 1024, but on a contract "kilo" will unequivocally mean 1000, unless explicitely defined as 1024 for the sake of that document.
> on a contract "kilo" will unequivocally mean 1000, unless explicitely defined as 1024 for the sake of that document.
If we are talking about kilobytes, it could just as easily the opposite.
Unless you were referring to only contracts which you yourself draft, in which case it'd be whatever you personally want.
Knuth thought the international standard promulgated naming (kibibyte) was DOA.
https://www-cs-faculty.stanford.edu/~knuth/news99.html
And he was right.
Context is important.
"K" is an excellent prefix for 1024 bytes when working with small computers, and a metric shit ton of time has been saved by standardizing on that.
When you get to bigger units, marketing intervenes, and, as other commenters have pointed out, we have the storage standard of MB == 1000 * 1024.
But why is that? Certainly it's because of the marketing, but also it's because KB has been standardized for bytes.
> Which is the reality. "kilobyte" means "1000 bytes". There's no possible discussion over this fact.
You couldn't be more wrong. Absolutely nobody talks about 8K bytes of memory and means 8000.
Ah, if only I had a dollar for every time I've had to point someone to the a tool like the following when trying to explain the difference between how much "bandwidth" their server has per month (an IEC unit) vs how fast the server connection is (a SI unit): https://null.53bits.co.uk/uploads/programming/javascript/dat...
I'm suprised they didn't mention kibibyte. (Edit: they did) There are plenty of applications where power-of-2 alignment are useful or necessary. Not addressing that and just chastising everyone for using units wrong isn't particularly helpful. I guess we can just all switch to kibibytes, except the HDD manufacturers.
We can, but we won't. At least not any time soon. For the foreseeable future, kilobyte will remain an ambiguous term, and kibibyte will very often not be used when someone is referring to 1024 bytes.
The second half of the article is entirely about kibibyte and the other IEC units.
It's at the end, in the "What are the standards units?" section.
So it does. I guess I skimmed a little too hard.
I've tried this approach with Lowes when I buy 2x4s. About as effective.
The author doesn't go far enough into the problems with trying to convert information theory to SI Units.
SI units are attempting to fix standard measurements with perceived constants in nature. A meter(Distance) is the distance light travels in a vacuum, back and forth, within a certain amount of ossilations of a cesium atom(Time). This doesn't mean we tweak the meter to conform to observational results as we'd all be happier if light really was 300 000KM/s instead of ~299 792km/s.
Then there's the problem of not mixing different measurement units. SI was designed to conform all measurements to the same base 10 exponents (cm, m, km versus feet inches and yards) But the authors attempt to resolve this matter doesn't even conform to standardised SI units as we would expect them to.
What is a byte? Well, 8 bits, sometimes. What is a kilobit? 1000 Bits What is a kilobyte? 1000 Bytes, or 1024 Bytes.
Now we've already mixed units based on what a bit or a byte even is and the addition of the 8 multiplier in addition to the exponent of 1000 or 1024.
And if you think, hey, at least the bit is the least divisible unit of information, That's not even correct. If there Should* be a reformalisation of information units, you would agree that the amount of "0"'s is the least divisible unit of information. A kilo of zero's, would be 1000. A 'byte' would be defined as containing up to 256 zero's. A Megazero would contain up to a million zero's.
It wouldn't make any intuitive sense for anyone to count 0's, which would automatically convert your information back to base 10, but it does prove that the most sensible unit of information is already what we've had before, that is, you're not mixing bytes (powers of 2) with SI-defined units of 1000
<joke> How to tell a software engineer from a real one? A real engineer thinks that 1 kilobyte is 1000 bytes while software engineer believes that there are 1024 meters in a kilometer :-) </joke>
I wonder if some day people will use {"joke": ...} instead of <joke>
For all the people commenting as if the meaning of "kilo" was open to discussion... you are all from the United States of America, and you call your country "America", right?
I agree in principle, but does anyone else feel super awkward saying "mebibyte" and "gibibyte"?
It honestly sounds like how a diaper-wearing baby would mispronounce kilobyte.
"I will not sacrifice my dignity. We've made too many compromises already; too many retreats. They invade our space and we fall back. They assimilate entire worlds with awkward pronunciations. Not again. The line must be drawn here! This far, no further! And I will make them pay for what they've done to the kilobyte!"
Oh sure, and next you'll say a byte is 10 bits ....
The word "octet" is absolutely the kibibyte of "bits in a byte".
It’s the French word for “byte”. In France your computer has Ko/Mo/Go.
I can go along with that, mostly. When you say "octet", some old-timer with an IBM 650 can't go whining that kids these days can't even read his 7-bit emails.
From https://archive.org/details/byte-magazine-1977-02/page/n145/...:
“A byte was described as consisting of any number of parallel bits from one to six. Thus a byte was assumed to have a length appropriate for the occasion. Its first use was in the context of the input-output equipment of the 1950s, which handled six bits at a time.”
"byte" doesn't even remotely resemble any decimal prefix, so it's okay. The problem is that prefixes "kilo", "mega", etc. are supposed to be decimal prefixes, but are used as binary. And what's worse, they aren't used consistently, sometimes they really mean decimal magnitudes, sometimes they don't.
A metric kilobyte is 1000 bytes. An imperial kilobyte, on the other hand, is 5280 bytes.
Nah, an imperial kilobyte is 5280 bits. That's way more plausible.
It is good that the old ways have not been forgotten. We used to argue about tabs vs. spaces, GPL vs. BSD, Linux vs. BSD, FreeBSD vs. NetBSD, BSD 2 clause vs BSD 3 clause. It's important to complain about things pointlessly. Builds character.
Anyway, here's my contribution to help make everything worse. I think we should use Kylobyte, etc. when we don't care whether it's 1000 or 1024. KyB. See! Works great.
I like how the GNU coreutils seem to have done. They use real, 1024-byte kilobytes by default, but print only the abbreviation of the prefix so it's just 10K or 200M and people can pretend it stands for some other silly word if they want.
You can use `--si` for fake, 1000-byte kilobytes - trying it it seems weird that these are reported with a lowercase 'k' but 'M' and so on remain uppercase.
. . . it seems weird that these are reported with a lowercase 'k' but 'M' and so on remain uppercase.
For SI units, the abbreviations are defined, so a lowercase k for kilo and uppercase M for mega is correct. Lower case m is milli, c is centi, d is deci. Uppercase G is giga, T is tera and so on.
https://en.wikipedia.org/wiki/International_System_of_Units#...
Of course! I was being silly and just thinking of "k" for the smaller one and "K" for the bigger one.
Upper-K is for Kelvin, so can't be mixed in as a prefix in case someone decides to commit physics crimes and talk about temperature-mass (Kkg).
Not true. Several SI prefixes already overlap with units. m is both metre and milli-. T is tesla and tera-. c is a prefix of candela (cd) but also centi-. (G is gauss (cgs unit, not mks/SI) and giga-.)
Just throw some Joules on top there and it'll be alright
I automatically assume that people that use KB=1000B want to sell me something (and provide less than promised), so should be aggressively ignored or removed from vicinities
KB is 1024 bytes, and don't you dare try stealing those 24 bytes from me
You think the people selling RAM are somehow more virtuous than the people selling hard disks?
https://en.wikipedia.org/wiki/DRAM_price_fixing_scandal
ITT: People who will vehemently talk about how everyone should convert to SI metric, except when it pertains to their personal favorite unit.
The entire reason "storage vendors prefer" 1000-based kilobytes is so that they could misrepresent and over-market their storage capacities, getting that 24-bytes per-kb of expectation-vs-reality profit.
It's the same reason—for pure marketing purposes—that screens are measured diagonally.
Not sure about that, SSDs historically have followed base-2 sizes (think of it as a legacy from their memory-based origins). What does happen in SSDs is that you have overprovisioned models that hide a few % of their total size, so instead of a 128GB SSD you get a 120GB one, with 8GB "hidden" from you that the SSD uses to handle wear leveling and garbage collection algorithms to keep it performing nicely for a longer period of time.
More recently you'd have, say, a 512GB SSD with 512GiB of flash so for usable space they're using the same base 10 units as hard disks. And yes, the difference in units happens to be enough overprovisioning for adequate performance.
Sounds like an urban legend. How likely is it that the optimal amount over-provisioning just so happens to match the gap between power-ten and power-two size conventions?
It doesn't, there's no singular optimal amount of over-provisioning. And that would make no sense, you'd have 28% over-provisioning for a 100/128GB drive, vs 6% over-provisioning for a 500/512GB drive, vs. 1.2% over-provisioning for a 1000/1024GB drive.
It's easy to find some that are marketed as 500GB and have 500x10^9 bytes [0]. But all the NVMe's that I can find that are marketed as 512GB have 512x10^9 bytes[1], neither 500x10^9 bytes nor 2^39 bytes. I cannot find any that are labeled "1TB" and actually have 1 Tebibyte. Even "960GB" enterprise SSD's are measured in base-10 gigabytes[2].
0: https://download.semiconductor.samsung.com/resources/data-sh...
1: https://download.semiconductor.samsung.com/resources/data-sh...
2: https://image.semiconductor.samsung.com/resources/data-sheet...
(Why are these all Samsung? Because I couldn't find any other datasheets that explicitly call out how they define a GB/TB)
It doesn't, but it's convenient.
Since 1000 is 3e8, I’ll argue that it should be 300000000 bytes.
It's not clear whether you are asking a question, proposing a new standard, or affirming an existing convention.
It's too late. Powers-of-two won. I'm the sort of person who uses "whom" in English, but even I acknowledge that using "KB" to mean 1,000, not 1,024, can only breed confusion. The purpose of language is to communicate. I'm all for pedantry when it's compatible with clarity, but we can't reconcile the two goals here.
No it didn't, look at your flash/hard drive labels. Also, there has been confusion since the beginning, and the core cause of confusion is refusing to use the common meaning of K, so insisting on that is just perpetuating said confusion
Is it? Outside of Windows, I rarely ever see KB used to mean 1024 anymore. Linux and Mac usually uses KB for 1000, and "K" or "Ki" or "KiB" for 1024.
KiB is a an abbreviation for "kilobyte" which emphasizes that it means 1024.
No it’s not. KiB is an abbreviation for kibibyte
Eg https://en.wikipedia.org/wiki/Kilobyte
Those silly words only come up in discussions like this. I have never heard them uttered in real life. I don't think my experience is bizarre here - actual usage is what matters in my book.
To be honest, I think the power-ten SI people might have won the war against the power-two people if they'd just chosen a prefix that sounded slightly less ridiculous than "kibibyte".
What the hell is a "kibibyte"? Sounds like a brand of dog food.
I genuinely believe you're right. It comes across like "the people who are right can use the disputed word, and the people who are wrong can use this infantile one".
I don't know what the better alternative would have been, but this certainly wasn't it.
Thinking about it a bit, I think I'd have
1. defined traditional suffixes and abbreviations to mean powers of two, not ten, aligning with most existing usages, but...
2. deprecated their use, especially in formal settings...
3. defined new spelled-out vocabulary for both pow10 and pow2 units, e.g. in English "two megabytes" becomes "two binary megabytes" or "two decimal megabytes", and...
4. defined new unambiguous abbreviations for both decimal and binary units, e.g. "5MB" (traditional) becomes "5bMB" (simplified, binary) or "5dMB" (simplified, decimal)
This way, most people most of the time could keep using the traditional units and be understood just fine, but in formal contexts in which precision is paramount, you'd have a standard way of spelling out exactly what you meant.
I'd have gone one step further too and stipulate that truth in advertising would require storage makers to use "5dMB" or "5 decimal megabytes" or whatever in advertising and specifications if that's what they meant. No cheating using traditional units.
(We could also split bits versus bytes using similar principles, e.g. "bi" vs "by".)
I mean consider UK, which still uses pounds, stone, and miles. In contexts where you'd use those units, writing "10KB" or "one megabyte" would be fine too.
That’s basically what Kibi et al is though. It’s Ki(lo) bi(nary) — kibi.
Yeah it sounds dumb, but it’s really not that different from your suggestion.
That seems like a better approach, and one that would've won me over.
It's leagues better than "kibibyte".
> 1 kilobyte is precisely 1000 bytes
Agreed. For the naysayers out there, consider these problems:
* You have 1 "MB" of RAM on a 1 MHz system bus which can transfer 1 byte per clock cycle. How many seconds does it take to read the entire memory?
* You have 128 "GB" of RAM and you have an empty 128 GB SSD. Can you successfully hibernate the computer system by storing all of RAM on the SSD?
* My camera shoots 6000×4000 pixels = exactly 24 megapixels. If you assume RGB24 color (3 bytes per pixel), how many MB of RAM or disk space does it take to store one raw bitmap image matrix without headers?
The SI definitions are correct: kilo- always means a thousand, mega- always means a million, et cetera. The computer industry abused these definitions because 1000 is close to 1024, creating endless confusion. It is a idiotic act of self-harm when one "megahertz" of clock speed is not the same mega- as one "megabyte" of RAM. IEC 60027 prefixes are correct: there is no ambiguity when kibi- (Ki) is defined as 1024, and it can coexist beside kilo- meaning 1000.
The whole point of the metric system is to create universal units whose meanings don't change depending on context. Having kilo- be overloaded (like method overloading) to mean 1000 and 1024 violates this principle.
If you want to wade in the bad old world of context-dependent units, look no further than traditional measures. International mile or nautical mile? Pound avoirdupois or Troy pound? Pound-force or pound-mass? US gallon or UK gallon? US shoe size for children, women, or men? Short ton or long ton? Did you know that just a few centuries ago, every town had a different definition of a foot and pound, making trade needlessly complicated and inviting open scams and frauds?
> The computer industry abused these definitions because 1000 is close to 1024, creating endless confusion.
They didn't abuse the definitions. It's simply the result of dealing with pins, wires, and bits. For your problems, for example, you won't ever have a system with 1 "MB" of RAM where that's 1,000,000 bytes. The 8086 processor had 20 address lines, 2^20, that's 1,048,576 bytes for 1MB. SI units make no sense for computers.
The only problem is unscrupulous hardware vendors using SI units on computers to sell you less capacity but advertise more.
> They didn't abuse the definitions.
Yes they did. Kilo- means 1000 in SI/metric. The computer industry decided, "Gee that looks awfully close to 1024. Let's sneakily make it mean 1024 in our context and sell our RAM that way".
> It's simply the result of dealing with pins, wires, and bits. For your problems, for example, you won't ever have a system with 1 "MB" of RAM where that's 1,000,000 bytes.
I'm not disputing that. I'm 100% on board with RAM being manufactured and operated in power-of-2 sizes. I have a problem with how these numbers are being marketed and communicated.
> SI units make no sense for computers.
Exactly! Therefore, use IEC 60027 prefixes like kibi-, because they are the ones that reflect the binary nature of computers. Only use SI if you genuinely respect SI definitions.
> Exactly! Therefore, use IEC 60027 prefixes like kibi-, because they are the ones that reflect the binary nature of computers. Only use SI if you genuinely respect SI definitions.
You have to sort of remember that these didn't exist at the time that "kilobyte" came around. The binary prefixes are — relatively speaking — very new.
> Yes they did. Kilo- means 1000 in SI/metric.
I'm happy to say it isn't an SI unit. Kilo meaning 1000 makes no sense for computers, so lets just never use it to mean that.
> Therefore, use IEC 60027 prefixes like kibi-,
No. They're dumb. They sound stupid, they were decades too late, etc. This was a stupid plan. We can define Kilo as 1024 for computers -- we could have done that easily -- and just don't call them SI units if that makes people weird. This is how we all actually work. So rather than be pedantic about it lets make the language and units reflect their actual usage. Easy.
Well, you're joking, but the entire RAM industry still lists their chips in Gb (gigaBITS) to avoid confusion.
32 Gb ram chip = 4 GiB of RAM.
That's still wrong and you've solved nothing. 32 Gb = 32 000 000 000 bits = 4 000 000 000 bytes = 4 GB (real SI gigabytes).
If you think 32 Gb are binary gibibits, then you've disagreed with Ethernet (e.g. 2.5 Gb/s), Thunderbolt (e.g. 40 Gb/s), and other communication standards.
That's why I keep hammering on the same point: Creating context-dependent prefixes sows endless confusion. The only way to stop the confusion is to respect the real definitions.
It's not wrong. It's the standard definition for that industry.
Damn you're right. It's double-confusing now.
I refuse to say "kibibyte" out loud
No, it's not. A kilobyte is 1,024 bytes.
I remember when they invented kibibytes and mibibytes and shaking my head and being like they have forever destroyed the meaning of words and things will be off by 2% forever. And is has been.
I propose we use footbyte, milebyte, inchbyte.
... And a hacker is precisely a cyber-criminal.
Nope.
It would be nice to have a different standard for decimal vs. binary kilobytes.
But if Don Knuth thinks that the "international standard" naming for binary kilobytes is dead on arrival, who am I to argue?
https://www-cs-faculty.stanford.edu/~knuth/news99.html
Just to show that disinformation exists in every field.
Metric prefixing should only be used with the unit bit. There is no confusion there. I mean, if you would equate a bit with a certain voltage threshold, you could even argue about fractional bits.
Approximating metric prefixing with kibi, Mibi, Gibi... is confusing because it doesn't make sense semantically. There is nothing base-10-ish about it.
I propose some naming based on shift distance, derived from the latin iterativum. https://en.wikipedia.org/wiki/Latin_numerals#Adverbial_numer...
* 2^10, the kibibyte, is a deci (shifted) byte, or just a 'deci'
* 2^20, the mibibyte, is a vici (shifted) byte, or a 'vici'
* 2^30, the gibibyte, is a trici (shifted) byte, or a 'trici'
I mean, we really only need to think in bytes for memory addressing, right? The base doesn't matter much, if we were talking exabytes, does it?
One thing that annoys me is:
Why don’t kilobyte continue to mean 1024 and introduce kilodebyte to mean 1000. Byte, to me implies a binary number system, and if you want to introduce a new nomenclature to reduce confusion, give the new one a new name and let the older of more prevalent one in its domain keep the old one…
Because kilo- already has a meaning. And both usages of kilobyte were (and are) in use. If we are going to fix the problem, we might as well fix it right.
Sure outside of computing in other science it has a meaning but in binary computing traditionally prefix + byte implied binary number quantities.
Many things acquire domain specific nuanced meaning ..
Even in computing the binary definition is only used with memory sizes. E.g. storage, network speeds, clock rates use the standard definition.
And yet in computing, a 1kHz clock is still 1000 cycles per second, and 1 MFLOP is still 1,000,000 floating-point operations per second.
The comment you replied to explained that:
"in binary computing traditionally prefix + byte implied binary number quantities."
There are no bytes involved in Hz or FLOPs.
> Why don’t kilobyte continue to mean 1024
Because it never did!
Which universe do you hail from? Because nobody except pedants have relented to this demand from non-computer scientists to conform to a standardization that has nothing to do with them or the work they do.