Binary prefix

In computing, binary prefixes are often used to quantify large numbers where powers of two are more useful than powers of ten. They are commonly written and pronounced identically to the SI prefixes, but each successive prefix is multiplied by 1024 (2¹⁰) rather than 1000 (10³). Using the prefixes kilo-, mega-, giga-, etc., and their symbols K, M, G, etc., in the binary sense can cause serious confusion. The International Electrotechnical Commission introduced the prefixes ''kibi-'', ''mebi-'', ''gibi-'', etc., and the symbols Ki, Mi, Gi, etc. to specify binary multiples of a quantity. == Binary prefixes using SI symbols (Non-standard usage) == {| border="1" align="center" cellpadding="3" cellspacing="0" |----- bgcolor=#ccccff ! Name ! Symbol ! Value ! Base 16 ! Base 10 |----- | kilo || k or K | 2¹⁰ = 1 024 | = 16^2.5 | > 10³ |----- bgcolor=#ffff99 | mega || M | 2²⁰ = 1 048 576 | = 16⁵ | > 10⁶ |----- | giga || G | 2³⁰ = 1 073 741 824 | = 16^7.5 | > 10⁹ |----- bgcolor=#ffff99 | tera || T | 2⁴⁰ = 1 099 511 627 776 | = 16¹⁰ | > 10¹² |----- | peta || P | 2⁵⁰ = 1 125 899 906 842 624 | = 16^12.5 | > 10¹⁵ |----- bgcolor=#ffff99 | exa || E | 2⁶⁰ = 1 152 921 504 606 846 976 | = 16¹⁵ | > 10¹⁸ |----- | zetta || Z | 2⁷⁰ = 1 180 591 620 717 411 303 424 | = 16^17.5 | > 10²¹ |----- bgcolor=#ffff99 | yotta || Y | 2⁸⁰ = 1 208 925 819 614 629 174 706 176 | = 16²⁰ | > 10²⁴ |} The one-letter abbreviations are identical to SI prefixes, except for "K", which is used interchangeably with "k" (in SI, "K" stands for the kelvin, and ''only'' "k" stands for 1000). Some have suggested that "k" be used for 1000, and "K" for 1024, but this cannot be extended to the higher order prefixes and has never been widely recognised. Notice that as the order of magnitude increases, the percentage difference between the binary and decimal values of a prefix increases, from 2.4% at kilo to over 20.8% at yotta. === Approximate ratios between binary prefixes and their decimal equivalent === {| border="1" cellpadding="3" cellspacing="0" |- bgcolor=#ccccff ! Name ! Bin > Dec ! Dec > Bin ! Example ! Percentage difference |- |kilobyte : kibibyte |1.024 |0.976 |100 KB = 97.6 KiB |2.4% |- |megabyte : mebibyte |1.049 |0.954 |100 MB = 95.4 MiB |4.9% |- |gigabyte : gibibyte |1.074 |0.931 |100 GB = 93.1 GiB |7.4% |- |terabyte : tebibyte |1.100 |0.909 |100 TB = 90.9 TiB |10% |- |} Informally, the prefixes are often used on their own. Thus one might hear about "a 40K file" (40 ''binary'' kilobytes) or "a 2M internet connection" (2 ''decimal'' megabits per second). What units are being used, and whether the multipliers are decimal or binary, depends on exactly what is being measured. == IEC standard prefixes == In 1999, the International Electrotechnical Commission (IEC) published Amendment 2 to "IEC 60027-2: Letter symbols to be used in electrical technology – Part 2: Telecommunications and electronics". This standard, which was approved in 1998, introduced the prefixes ''kibi-'', ''mebi-'', ''gibi-'', ''tebi-'', ''pebi-'', ''exbi-'', to be used in specifying binary multiples of a quantity. The names come from the first two letters of the original SI prefixes followed by ''bi'' which is short for "binary". It also clarifies that, from the point of view of the IEC, the SI prefixes only have their base-10 meaning and never have a base-2 meaning. This amendment was included in the next edition of the standard: "IEC 60027-2 (2000-11) Ed. 2.0" As of 2005 this naming convention has not gained widespread use, but its use is growing. It is strongly supported by many standardization bodies, including IEEE and CIPM. {| border="1" cellpadding="3" cellspacing="0" align="center" |- bgcolor=#ccccff ! Name !! Symbol !! Value |- | kibi || Ki || 2¹⁰ = 1 024 |- bgcolor=#ffff99 | mebi || Mi || 2²⁰ = 1 048 576 |- | gibi || Gi || 2³⁰ = 1 073 741 824 |- bgcolor=#ffff99 | tebi || Ti || 2⁴⁰ = 1 099 511 627 776 |- | pebi || Pi || 2⁵⁰ = 1 125 899 906 842 624 |- bgcolor=#ffff99 | exbi || Ei || 2⁶⁰ = 1 152 921 504 606 846 976 |} ''Example :'' 300 GB = 279.5 GiB (= hexadecimal117.6592E GiB = 0x45D96.4B8 MiB = 0x1176592E KiB = 0x45D964B800 bytes). Note that the IEC names are defined only up to ''exbi-'', corresponding to the SI prefix ''exa-''. The two SI prefixes ''zetta-'' (10²¹) and ''yotta-'' (10²⁴) have no corresponding IEC binary prefixes, though the obvious continuation would be ''zebi-'' (Zi = 2⁷⁰ = 1000⁷ � 1.180 591 620 717 411 303 424) and ''yobi-'' (Yi = 2⁸⁰ = 1000⁸ � 1.208 925 819 614 629 174 706 176). == Usage notes == We will use the phrase "decimal unit" to mean "SI designation understood in its standard, decimal, power-of-1000 sense" and "binary unit" to mean "SI designation understood in its traditional computer-industry, binary, power-of-1024 sense." Also following the tradition of computer confusion, the symbol for byte used here is B, which in SI stands for the decibel. It has oft been recommended to use b for the byte, but that is also sometimes used for the bit (the other symbol used is bit). This issue is not about to be resolved, as SI does not deal with units of quantity of information. Certain units are always understood as decimal even in computing contexts. For example, hertz (Hz), which is used to measure clock rates of electronic components, and bit/s, used to measure bitrate. So a 1 GHz processor performs 1,000,000,000 clock ticks per second, a 128 kbit/s MP3 stream consumes 128,000 bits (15.625 KiB) per second, and a 1 Mbit/s internet connection can transfer 1,000,000 bits (approx. 122 KiB) per second. Measurements of electronic memory such as Random Access Memory and Read-only memory are given in binary units, because the physical structure of the device makes it naturally come in sizes that are powers of two. This is the case whether the capacity is given in bits or bytes. Hard disk drive manufacturers state capacity in decimal units, so what is advertised as a "30 GB" hard drive will hold 30 × 10⁹ bytes, roughly equal to 28×2³⁰ bytes (i.e. 28 GiB). This usage has a long engineering tradition, and was probably ''not'' influenced by marketing. It arose because nothing about the physical structure of the disk drives makes power-of-two capacities natural: the number of platters, tracks and sectors per track are all continuously variable. Disk media are accessed by the sector, not the individual byte. Sectors are intended for direct transfer to RAM, which comes in powers of two, so sector size itself is almost always a power of two. Common sector sizes range from 512 bytes (e.g. on floppy disks) to 2048 bytes (DVDs). Because of this, a very confusing hybrid system is sometimes used, in which a "megabyte" means a thousand 1024-byte "kilobytes". Thus, as of 2005, manufacturers universally use the designation "1.44 MB floppy disk" for a product which holds neither 1.44 × 2²⁰ bytes nor 1.44 × 10⁶ bytes, but rather 1.44 × 1000 × 1024 bytes (approximately 1.406 MiB, or 1.475 MB). Modern-day PC users, of course, regard both RAM and disk as kinds of storage and expect their capacities to be measured in the same way. Operating systems usually report HD space using the binary version. To the purchaser of a "30 GB" hard drive, rather than reporting either "30 GB" or "28 GiB", Microsoft Windows reports "28 GB". This creates hard feelings, sometimes made worse by other technical issues such as failure to distinguish between unformatted and formatted capacities. compact disc capacities are always given in binary units. A "700 MB" (or "80 minute") CD has a nominal capacity of about 700 MiB. But DVD capacities are given in decimal units. A "4.7 GB" DVD has a nominal capacity of about 4.38 GiB. Decimal versions are used when dealing with Computer bus bandwidth (e.g. "Ultra SCSI has a bandwidth of 40 megabytes per second"). Interestingly, this is not because hard drive capacities use the decimal versions, or because bitrates do, but because clock speeds do. ==See also== *Integral data type *Bit *Nibble *Byte *Octet *IEC 60027-2 *SI prefix === Specific units ===

==External links== * [http://www.cl.cam.ac.uk/~mgk25/information-units.txt Markus Kuhn's 1996-1999 paper on bits, bytes, prefixes and symbols] * [http://physics.nist.gov/cuu/Units/binary.html NIST page on binary prefixes] * [http://www.iec.ch/zone/si/si_bytes.htm IEC description of binary prefixes] * [http://www.quinion.com/words/turnsofphrase/tp-kib1.htm Another description, by Michael Quinion] * [http://www.nist.gov/public_affairs/techbeat/tb9903.htm#Information%20Technology Get Ready for the mebi, gibi and tebi (NIST TechBeat)] * [http://www.wiebetech.com/pressreleases/BillionEqualBillion.pdf WiebeTech (drive manufacturer) white-paper on the controversy over drive capacities] * [http://homepages.tesco.net/~J.deBoynePollard/FGA/1mb44-is-not-a-standard-floppy-disc-size.html "There is no such thing as a 1.44MB standard format floppy disc."], by Jonathan de Boyne Pollard * [http://members.optus.net/alexey/prefBin.xhtml A summary of the organizations, software, and so on that have implemented the new binary prefixes] * [http://www.xciv.org/~meta/2005/02/25/#2005-02-23-units "A plea for sanity"] Computing Prefixes Measurement Naming conventions

Binary prefix

== Binary or decimal context implied by electronic memory == In the page, I see the quote: Electronic memory such as RAM and ROM always uses the binary versions, because the physical structure of the device makes it naturally come in sizes that are powers of two. This isn't true, but I don't yet know how to fix it concisely, help. For example, flash is an electronic memory, and ECC-protected RAM is an electronic memory, but their capacities aren't naturally powers of two. A concise true alternative I saw said recently was: The RAM and ROM folk gave us this confusion by behaving as if memory were reliable. That is, by converting to precise binary prefixes from loose decimal approximations, they left no room for Error-correcting_code, etc. In more detail ... All that's naturally a power of two in memory is the count of raw cells in a single layer. Yes, P * Q cells appear in a rectangular array. P * Q is a power of 2 because P and Q are powers of 2. P and Q are powers of 2 because pins cost much money. If you make N pins into an address bus, then you can address 2^N rows or columns. Yes. So far so good. But electronic memory today - 2005 - often contains a lot more than a single layer of raw 1 or 0 cells. As in modems, so now in memory cells, the discrete stored voltage may be multilevel, e.g., representing 0 or 1 or 2 or 3 or 4, not always binary. The chip may contain more than one layer. Part of the chip may be dedicated to ECC, or left free for wear-leveling. Consequently, the capacity of flash memory in particular is now "continuously variable", and their physicists follow the HDD physicists by using the standard metric units to count bits. == Discussion of page name == This page needs a rename as part of the "Kill your friendly neighbourhood stub" campaign. Any suggestions? At the risk of sounding a little audacious, I suggest a renaming from "Byte/Prefixes" to "Byte prefixes" ;-) -- User:Tarquin I find it a bit confusing to have the first table listing the deprecated usage of the prefixes. Maybe it's better to have the first table listing the current standard, then have the colloquial usage listed much later in the article... User:Bob Jonkman03:33 Oct 14, 2002 (UTC) : Better yet, kill the first table altogether. The bottom half is superfluous anyway. I have ''never'' seen "yotta" being used meaning 2^80, except by a handful of nerds at Wikipedia... ;-)
User:Herbee 02:52, 2004 Feb 21 (UTC) Change "Byte" to "Binary", because these prefixes are also applied to other units such as bits and words (as the introductory text clearly says!) -- User:Dwheeler 21:26 21 May 2003 (UTC) ==The mythical nona- and dogga- == User:81.63.111.215 added the phrase "as well as nobi- and dogbi-", presumably based on the assumption that there are legitimate decimal-based prefixes nona- for 10²⁷ and dogga- for 10³⁰. They are ''not'' SI prefixes, or at least NIST knoweth not of them. I'm perfectly prepared to be convinced of their existence, but I want to see ''some'' evidence that ''some'' recognized standards organization is promulgating them. I have so far found nothing but loose assertions in Google searches. User:Dpbsmith 00:27, 21 Mar 2004 (UTC) :The [http://www.bipm.fr/en/si/prefixes.html official list of prefixes] is maintained by the Bureau International des Poids et Mesures. Consider that evidence against this nonsense. :—User:Herbee 02:37, 2004 Mar 21 (UTC) :: Thanks for keeping up on all of this, dpb. User:Sj+">User Talk:Sj == From VfD, re: Zebi/Yobibyte == *According to what I hear at Wikipedia, IEC has officially coined kibibyte through exbibyte, but not zebibyte or yobibyte. Any significance of these 2 articles?? User:66.245.22.210 16:53, 3 Aug 2004 (UTC) *Delete both - dicdefs, and also delete if they are not official terms - User:TextureUser Talk:TextureUser:Texture 17:20, 3 Aug 2004 (UTC) *Weak vote to delete. If they are not the official terms, then they should go. If they ever get certified, they can be recreated. -- User:DropDeadGorgias User_talk:DropDeadGorgias 17:33, Aug 3, 2004 (UTC) *~~Delete.~~ Redirect to Binary prefix where they are mentioned and properly identified as speculative. Sans such a qualification, these articles are misinformation, because the terms have not been endorsed by any standards organization, are not in any dictionary, and are not in significant use (because as of 2004 they are too big for there to be any actual need for them). This is very similar to the issue with Nonabyte and Doggabyte which were deleted per VfD some time ago. Nerd oneupmanship. If these are not deleted, I shall contribute my own fine articles on "bajillion skillion gazillion antidisestablishmentillion," and "mobidikkabyte" (=the binary equivalent of one melvillion bytes) User:dpbsmith_User_talk:dpbsmith">User:Dpbsmith|User:dpbsmith User_talk:dpbsmith 20:24, 3 Aug 2004 (UTC) * Keep. Zetta- and yotta- are SI prefixes [http://physics.nist.gov/cuu/Units/prefixes.html]. Some prefixes have modified forms for naming powers of 2 [http://physics.nist.gov/cuu/Units/binary.html]. Zetta- and yotta- don't appear to have official binary forms but it's easy enough to see that zebi- and yobi- would be those forms if they did, and every now and then somebody makes that obvious extrapolation, e.g. [http://www.gnu.org/software/coreutils/manual/html_node/coreutils_4.html]. Zebibyte and yobibyte should state explicitly that they're unofficial terms. I'd do that but I'm feeling lazy at the moment. User:Wile E. Heresiarch 15:06, 4 Aug 2004 (UTC) ::Hmph. Such extrapolations can surely be made, but they're not encyclopedic. Wikipedia is not a crystal ball. I feel very confident that Kerry will take Massachusetts in the 2004 U. S. Presidential election, but that does not mean that I should write an encyclopedia article that states this as fact. Wikipedia is accumulating enough of this sort of garbage to be of at least mild concern. User:dpbsmith_User_talk:dpbsmith">User:Dpbsmith|User:dpbsmith User_talk:dpbsmith 16:18, 4 Aug 2004 (UTC) P. S. Too many nerds have obviously gotten too many pats on the back for being able guess "what comes next" in a sequence... * Modify and keep as outlined by Wile. - User:UtherSRG 15:44, 4 Aug 2004 (UTC) * Modify and keep. User:Spiff 17:12, 4 Aug 2004 (UTC) ::Well, I've done a modify since if the articles are going to be, ugh, kept I want them to be accurate. With regard to User:Wile E. Heresiarch's citation [http://www.gnu.org/software/coreutils/manual/html_node/coreutils_4.html] I do not see "zebibyte", "zebi-", "yobibyte", or "yobi-." I indeed see the ''abbreviations'' ZiB and YiB, and the (puzzling) explanation that "`Zi'[sic] is a GNU extension to IEC 60027-2." Presumably that's a typo for ZiB. Ditto for YiB. If accurately described and cited, I wouldn't object to this factoid being added to the article, since IMHO the FSF does count as some kind of authority—perhaps as an external link identified as "Use of abbreviations ZiB and YiB in GNU software." User:dpbsmith_User_talk:dpbsmith">User:Dpbsmith|User:dpbsmith User_talk:dpbsmith 17:32, 4 Aug 2004 (UTC) * Delete. Redirect these to Binary prefix for now. If and when they become standard, they can have their own articles. -- User:WOT 18:21, 4 Aug 2004 (UTC) * Delete. Checking google, most uses seem to either be wikipedia or reference wikipedia as the source of this info. The words just aren't useful. * Delete speculation. -- User:Cyrius|User talk:Cyrius 19:19, 6 Aug 2004 (UTC) *Delete. Newbiebyte. But you can't fool Mr. Metric. Patent nonsense. User:DwindrimUser_talk:Dwindrim 01:41, 2004 Aug 7 (UTC) *Delete... oh, I'm too late. Please delete, all the same. As dpb says, WP is not a crystal ball. In particular, we will now be used ''by others'' as the source confirming that these two variants are the binary equivalents of the SI forms, something WP we should under no circumstances be. User:Sj+">User Talk:Sj 17:36, 11 Aug 2004 (UTC) == Hexadecimal billion == The contents of this section "Hexadecimal billion" were transferred on a "archieved" page called ~~Closed talk: section Hexadecimal Billion in Talk:Binary prefix~~ Talk:Binary prefix/Hexadecimal Billion. Started from a different of opinion concerning the numerals corresponding to the values of the multiples of unit, like the prefix "Tebi" or "Tera binary", i.e. a "billion" according to Michael, and Ian who deleted while he considered this too ambiguous. Afterwards we talked about the significance of the terme "one billion hexadecimal". To make place for other discussions, Ian and Michael decided to not continue this discussion at this place more, also because we had moved away, finally, too much from "Binary prefix". If somebody would be interested to continue this discussion, that's now at User talk:Michael Chuquet/Hexadecimal billion. :Just for the record: the original archive was in the main article Wikipedia:Namespace, which is undesirable because the Special:Randompage feature can send a reader to it. I've moved the archive to a Wikipedia:Subpages of the talk namespace: Talk:Binary prefix/Hexadecimal Billion. User:BencUser_talk:Benc 04:48, 9 Oct 2004 (UTC) == Hard disk sizes == My Maxtor 40 GB is actually 38.2 GB (dd tells me it has 80022600 sectors, or 38.1577 MB). That's 39,073.5352 MB, 40,011,300 K, 40,971,571,200 bytes. OTOH, my Maxtor 160 GB has 320173056 sectors, or 152.67 GB. That's 156,334.5 MB, 160,086,528 K, 163,928,576,512 bytes. Clearly, if GB meant 1000*1024*1024 bytes, then they'd be giving me less than claimed (and I could sue them!). If GB meant 1000³ bytes, they'd be giving me almost a gig more for my 40 GB, and almost 4 gigs more for my 160 GB. They probably use 1 GB = 1000*1000*1024 bytes. But my Quantum Fireball advertises "4.0 GB" and actually has that much (assuming Windows is accurate), 4.0062 GB, 4102.32 MB, 4200776 K, 4301594624 bytes. It also says "4.3AT" and has "43" in the model number, which I assume refers to 4.3 decimal GB. Then, my Seagate 40 GB has 78163247 sectors, or 37.2711 GB, 38165.6479 MB, 39081623.5 K, 40019582464 bytes. It ''should'' have 78165360 sectors (according to the specs), no idea why it has less. It'd be false advertising unless GB meant 1000*1000*1000 bytes. Western Digital seems to use 1 GB = 1000*1000*1000 bytes, as well (which means it was worth paying more for my Maxtor). Hitachi seems to use 1000*1000*1024 bytes. So we have one company using 1024³ (except I have no recent HDs from Quantum, and they don't seem to make them anymore), two companies using 1000²*1024, and two more using 1000³. User:Elektron 22:25, 2004 Aug 30 (UTC) Also, Toshiba uses 1 GB = 1000³ bytes, so does Fujitsu. Samsung says they use 1000³, and [http://www.samsung.com/Products/HardDiskDrive/utilities/hutil.htm not-so-official sector counts] appear to confirm this. Since Quantum doesn't make hard disks anymore, for current hard disks, we have two companies using 1000²*1024, and five using 1000³ User:Elektron 23:36, 2004 Aug 30 (UTC) == Consolidate all the little articles == I propose that all the little articles: {| style="text-align:left;" ! style="width:7em;" | SI, bits ! style="width:7em;" | SI, bytes ! style="width:7em;" | IEC, bits ! style="width:7em;" | IEC, bytes |- | Kilobit | Kilobyte | Kibibit | Kibibyte |- | Megabit | Megabyte | Mebibit | Mebibyte |- | Gigabit | Gigabyte | Gibibit | Gibibyte |- | Terabit | Terabyte | Tebibit | Tebibyte |- | Petabit | Petabyte | Pebibit | Pebibyte |- | Exabit | Exabyte | Exbibit | Exbibyte |- | Zettabit | Zettabyte | — | — |- | Yottabit | Yottabyte | — | — |} should be consolidated into this article (without destroying any useful information). If they are not, then someone should at least go through them all and lowercase all of them. Unit names are always lowercase. For instance: "The Gibibyte is closely related to the Gigabyte, which is..." should be "The gibibyte is closely related to the gigabyte, which is...", etc. - User:Omegatron 03:44, Sep 24, 2004 (UTC) :I concur, but really, the SI "gigabyte" isn't really a 'binary prefix'. One day I think I'll have to do this though. User:Elektron 20:01, 2004 Nov 1 (UTC) ::Why not? That's what this article is about; using giga and gibi as binary prefixes. The individual "small" articles are getting bigger, though. - User:Omegatron 20:17, Nov 1, 2004 (UTC) I still think all the little articles should be combined into this article. Kibibyte, for instance, has info that is not in Mebibyte. It's really silly to have a separate article for each one, that basically only contains a single number and it's relation to two other numbers. All of that info should be in this article, and then the info that isn't doubled everywhere will be in one place. - User:Omegatron 18:57, Dec 21, 2004 (UTC) :Nobody objected, so go ahead and do it if you want. User:Smyth\^{User_talk:Smyth}">User:Smyth|– User:Smyth\^{User_talk:Smyth} 19:36, 21 Dec 2004 (UTC) ::Nobody said it was a good idea, either. Plus it will take some significant work with the bigger articles like megabyte. Don't wanna change it if everyone is suddenly going to say "no that was bad" and revert it. - User:Omegatron 14:22, Dec 29, 2004 (UTC) I thought this sort of thing was already done with other articles like kilowatt, attogram, and so on, except now that I look, they all have little articles for each. Hmm... Has there been discussion about this for other units? - User:Omegatron 22:21, Dec 30, 2004 (UTC) I agree that gigabyte shouldn't redirect here... it's not a binary prefix, and that would just confuse things. However, it wouldn't be a bad idea to go through all the articles and strip out all the information that belongs in more general articles (like this one) and replace it with a quick summary and link to the more comprehensive discussion, per Wikipedia:Summary style. The amount of duplication is distressing. User:68.81.231.127 :Good point. gigabit/byte should not redirect, i guess, even though they are binary prefixes in this instance (according to this article, giga, mega, etc. can be used as both binary prefixes and SI prefixes, though I think they should only be considered SI prefixes. but according to this very article, they ARE binary prefixes...) I already added the see also binary prefix to each article, but no one notices and just adds stuff to each individual article. - User:Omegatron 20:07, Jan 13, 2005 (UTC) :It's even worse.. those are SI prefixes, but they are not SI units because B is not an SI symbol for byte (or even Bel, at least not yet I think :). And then there are special case like the 1,024×1,000 megabyte variant.... :Anyway, a lot of articles seem to link to the kilo-, mega-, and giga- variants (150–250 for the -bytes series), while tera- is only linked about 50 times, and peta- and higher have <20 each. So at least the big three or four are natural links, and might justify their own articles. There are also enough special cases in the big three (which industry uses it, etc) that they'd still need separate sections in a big article, so it's probably easier to keep them separate. (I don't think it matters either way, but if the larger units ''are'' turned into redirects, they should probably be pointed to byte [or bit].) {| style="margin:0 auto;" class="toccolours" align=right |- ! colspan=2 style="background-color:#ccf; text-align:center;" | Byte unit (SI prefix) |- ! align=left | Other: ||kilo- | mega- | giga- | tera- | peta- | exa- | zeta- |- | colspan=2 align=center | Related bit unit: Megabit |- | colspan=2 align=center | Related binary prefix unit: Mebibyte |} :A bigger problem is reducing duplication of effort. There is very different text saying very similar things on different pages. A Wikipedia:Navigational templates could help with all the related units, while using a standard paragraph and pointer to the main articles here and at the SI prefix page using would clear out a lot of the rest (using Wikipedia:Summary style again... there is an example at Gigabyte#Distinction between 1000 and 1024 megabytes, though it needs a lot of work). The navigation template to the right needs some work, but really like simple over cluttered... ahem... Afrotropic is an abomination :). :I'm just playing with ideas... I'm not even sure this is the right approach. User:68.81.231.127 00:09, 14 Jan 2005 (UTC) Alright. If we're not going to consolidate all the little articles, we should add a template to all of them with all of the others on it. Anons search for "petabyte", find our article, and then start adding info about gigabytes, etc. We need to indicate that there already are articles about each particular value and also about this article. - User:Omegatron 01:16, Mar 24, 2005 (UTC) ==Template for Binary prefixes== I have created a template available at: which I would like to insert into this article. I would hope that this could enable aome rationalisation of the existing tables, and could perhaps eventually be inserted into all the individual binary prefix articles, e.g. kibi, mebi, etc (assuming that they are not merged beforehand). Does anyone have any objection or wish to edit the template beforehand (see edit link in top line of template)? User:Icairns 21:47, 15 Nov 2004 (UTC) :Looks good. pretty big though. maybe list only as powers of 10 and powers of 2? - User:Omegatron 22:55, Nov 15, 2004 (UTC) :Very good, but not 800x600 friendly. Alternating table row backgrounds would be nice though. --User:Delicates 03:09, 24 Nov 2004 (UTC) ::I've reduced the overall width by removing the number values. Is this any better, particularly for 800x600? (The alternating backgrounds will have to wait for another day...) User:Icairns 18:46, 24 Nov 2004 (UTC) :::Now I really don't like the middle section, and don't think it deserves a place under the sun due to it being inappropriately erroneous, and making the whole table ambiguous and confusing. Might want to put word "standard" as well into the SI heading. The IEC section lacks the 2ⁿ column which is more appropriate there. --User:Delicates 22:13, 24 Nov 2004 (UTC) ::::Thanks for that. I'm concerned that you think it's erroneous. Please can you indicate where the errors might be? The SI prefixes are known as such in Wikipedia, so I didn't see the need to include the word 'standard'. If they become known as SI standard prefixes, then I'm happy to change the template. Regarding the 2^n column, I was told that the table was too wide as it was previously. I was trying to avoid duplicating the same column. I have been wondering whether it might be possible to remove one of the 'kilo' columns to reduce the width further without generating confusion, but I don't think this can be done easily. Please can you indicate where you find the template confusing? Alternatively, be bold with your editing and let others review your changes. Thanks, User:Icairns 23:35, 24 Nov 2004 (UTC) :::::The problem I have with it is that it has two identical columns that contradict eachother which is both erroneous and confusing in context of the same table. I think the middle section should be taken out alltogether, because it is redundant in the presence of �≈� symbol, which makes the association of the SI prefixes with the binary meaning pretty clear. The only problem that with this is the inconsistent use of �k� and �K� for �kilobyte�. The people who find this page through a search engine won't be aware of SI prefixes being known in Wikipedia as standard. It is good to be consistent so that people don't have doubts when they see something applied to one thing but not to another. --User:Delicates 02:13, 25 Nov 2004 (UTC) ::::Given that Delicates thought the template was 'very good' at 03:09, I've added the template to the existing article, to see it in context - without thinking yet whether any of the existing tables can now be rationalised / avoided. User:Icairns 00:22, 25 Nov 2004 (UTC) pebi, mebi, etc. just redirect to this article, you know. - User:Omegatron 22:25, Dec 30, 2004 (UTC) == Do not include -zebi and -yobi == There are no such prefixes. They should not be included in a table that purports to be documenting the IEC standard. Everyone understand, and the article states explicitly, that they are the logical ''extension'' of the IEC system, but until and unless the IEC chooses to extend the system they should not be included. User:Dpbsmith User_talk:dpbsmith 19:35, 30 Jan 2005 (UTC) *PLEASE DO NOT reinsert these values into the table without discussion. They are ''not'' "unofficial extensions." They are ''not'' real terms at all. They are purely speculative; someone's guess as to what names would be used if these units had names. I believe, based on Google hits, that they are mostly a sort of nerdish urban legend propagated by people copying tables from teach other. Unless you can convince me otherwise by showing a good citation from a serious, authoritative source that shows the names "zebibyte" and "yobibyte" are in real use in the computer field, I will continue to feel that these should not be in the table of binary prefixes at all. I don't mind the sentence pointing out that -zebi and -yobi are the obvious continuations. I'm not at all sure it's necessary to give the numeric values of 2⁷⁰ and 2⁸⁰, but you wanted them there and I didn't see a problem with it. Change them to the 1000ⁿ×1.#### format if you think that provides more insight. But they should not go in the main table. User:Dpbsmith User_talk:dpbsmith 13:34, 4 Feb 2005 (UTC) ::I'm just not sure what harm there is in adding them to the table, properly identified as speculative. Why the allergy? As for giving the values, yes they are required because they're not easily calculated (i.e. they must be done by hand, unless you have some peculiar calculator available). Ah well, this is not worth an edit war, obviously. ::User:Urhixidur 00:51, 2005 Feb 5 (UTC) :::What's so hard about 1024 × = = = = = = = = on the calculator that comes with Windows and many other calculators? User:Gene Nygaard 01:02, 5 Feb 2005 (UTC) ::::The Calculator handles it, because it takes special care with large numbers. Excel, on the other hand, uses normal integers and thus fails to carry enough precision. ::::User:Urhixidur 15:47, 2005 Mar 27 (UTC) == B is for bel == In editing the article, User:Urhixidur commented " B is Bel, b recommended for byte". Big deal. B is also for boron. But you'd need to change that last b to an m to describe someone who imagines a likelihood of even as much confusion between bytes and bels (lowercase, of course) as there would be between boron and bels. #Why should bels get preference in any case? They aren't an SI unit, are only listed as acceptable for use with SI. #Bels and bytes are used in completely different fields of activity. #The bel is never used standing alone, and never used with any prefix other than "deci-". #Bytes are never used WITH the prefix "deci-". Those points are, of course, applicable even setting aside the reason I changed Urhixidur's edits in the first place; "b" is used as the symbol for "bits" in this article, and it would be silly to use the same symbol for "bytes" as well. User:Gene Nygaard 23:44, 30 Jan 2005 (UTC) One more point about SI: In SI, the radian (symbol rad) is a derived unit. The rad (symbol rad) is among the units in Table 10 of the BIPM brochure and in Table 9, temporarily accepted for use with the SI, in the NIST brochure. User:Gene Nygaard 00:01, 31 Jan 2005 (UTC) :� Why should bels get preference in any case? � :Because of the well established rule that upper-case symbols tand for units named after people, in this case Alexander Graham Bell. :� Those points are, of course, applicable even setting aside the reason I changed Urhixidur's edits in the first place; "b" is used as the symbol for "bits" in this article, and it would be silly to use the same symbol for "bytes" as well. � :There is not a single occurrence of "b" standing for bit anywhere in the article. :User:Urhixidur 01:30, 2005 Feb 5 (UTC) == We need a template for the little articles == I want to compromise the conciseness and prettiness of this: {| style="margin:0 auto;" class="toccolours" align=right |- ! colspan=2 style="background-color:#ccf; text-align:center;" | Byte unit (SI prefix) |- ! align=left | Other: ||kilo- | mega- | giga- | tera- | peta- | exa- | zeta- |- | colspan=2 align=center | Related bit unit: Megabit |- | colspan=2 align=center | Related binary prefix unit: Mebibyte |} with the info in this: {| border="1" cellspacing="0" width="50%" cellpadding="1" align=center style="margin:0 auto; background:#f3f9ff;" ! colspan="3" | Decimal prefixes

! ! colspan="7" | Binary prefixes

|- ! colspan="3" | SI prefixes
powers of ten ! ! colspan="3" | Binary prefixes
powers of two ! ! colspan="2" | Binary prefix#IEC standard prefixes
powers of two |- ! Prefix ! Symbol ! Multiple ! ! Prefix ! Symbol ! Multiple ! ! Prefix ! Symbol |- | yotta | Y | 1 E24 | ≈ | yotta | Y | 2⁸⁰ | | | |- | zetta | Z | 1 E21 | ≈ | zetta | Z | 2⁷⁰ | | | |- | exa | E | 1 E18 | ≈ | exa | E | 2⁶⁰ | = | exbi | Ei |- | peta | P | 1 E15 | ≈ | peta | P | 2⁵⁰ | = | pebi | Pi |- | tera | T | 1 E12 | ≈ | tera | T | 2⁴⁰ | = | tebi | Ti |- | giga | G | 1 E9 | ≈ | giga | G | 2³⁰ | = | gibi | Gi |- | mega | M | 1 E6 | ≈ | mega | M | 2²⁰ | = | mebi | Mi |- | kilo | k | 1 E3 | ≈ | kilo | k or K | 2¹⁰ | = | kibi | Ki |- | colspan="11" | Notes: *The SI prefixes have similar values to, but are different from, the corresponding Binary prefixes. The IEC prefixes were proposed to distinguish these meanings. *As of 2004, the IEC prefixes have not been widely taken up |} and create template that we can put in all the little articles like kilobit and pebibyte so newcomers realize each article has its own info already and stop trying to write the same info into one of the little articles. I basically just want to make this: {| style="text-align:left;" ! style="width:7em;" | SI, bits ! style="width:7em;" | SI, bytes ! style="width:7em;" | IEC, bits ! style="width:7em;" | IEC, bytes |- | Kilobit | Kilobyte | Kibibit | Kibibyte |- | Megabit | Megabyte | Mebibit | Mebibyte |- | Gigabit | Gigabyte | Gibibit | Gibibyte |- | Terabit | Terabyte | Tebibit | Tebibyte |- | Petabit | Petabyte | Pebibit | Pebibyte |- | Exabit | Exabyte | Exbibit | Exbibyte |- | Zettabit | Zettabyte | — | — |- | Yottabit | Yottabyte | — | — |} into a prettier navbox with a little more info. Ideas? - User:Omegatron 17:22, Mar 25, 2005 (UTC) === A little better === {| style="margin:0 auto; text-align:center;" class="toccolours" ! colspan="3" style="background-color:#ccf;" | Decimal SI prefixes
powers of ten ! ! colspan="3" style="background-color:#ccf;" | Binary Binary prefix#IEC standard prefixes
powers of two |- ! Prefix ! Symbol ! Multiple ! ! Prefix ! Symbol ! Multiple |- | style="text-align:left;" | kilo | k | 1 E3 | ≈ | style="text-align:left;" | kibi | Ki | 2¹⁰ |- | style="text-align:left;" | mega | M | 1 E6 | ≈ | style="text-align:left;" | mebi | Mi | 2²⁰ |- | style="text-align:left;" | giga | G | 1 E9 | ≈ | style="text-align:left;" | gibi | Gi | 2³⁰ |- | style="text-align:left;" | tera | T | 1 E12 | ≈ | style="text-align:left;" | tebi | Ti | 2⁴⁰ |- | style="text-align:left;" | peta | P | 1 E15 | ≈ | style="text-align:left;" | pebi | Pi | 2⁵⁰ |- | style="text-align:left;" | exa | E | 1 E18 | ≈ | style="text-align:left;" | exbi | Ei | 2⁶⁰ |- | style="text-align:left;" | zetta | Z | 1 E21 | | | | |- | style="text-align:left;" | yotta | Y | 1 E24 | | | | |- ! colspan="7" style="background-color:#ccf;" | These prefixes are often applied to byte and bit. |} How about this? Feel free to come up with a better/smaller phrase/sentence to put at the bottom. Variants I thought about: "applied to", "added to", "used with", remove word "prefixes", add word "terms", and so on... What do you think? Also, if we nuke all those dictdef articles we should make sure any interesting info like in petabyte is preserved into the common byte article. Oh and we gotta think of the name for the template. User:Delicates 19:44, 16 Apr 2005 (UTC) ---- * I like it. — User:SebastianHelm 07:11, 2005 Mar 27 (UTC) :Hmm.. That's better, but I wanted to link directly to articles like yottabyte, not yotta :Basically I want this made into a smaller, prettier navbox: - User:Omegatron 16:40, Mar 27, 2005 (UTC) {| style="text-align:left;" ! style="width:7em;" | SI, bits ! style="width:7em;" | SI, bytes ! style="width:7em;" | IEC, bits ! style="width:7em;" | IEC, bytes |- | Kilobit | Kilobyte | Kibibit | Kibibyte |- | Megabit | Megabyte | Mebibit | Mebibyte |- | Gigabit | Gigabyte | Gibibit | Gibibyte |- | Terabit | Terabyte | Tebibit | Tebibyte |- | Petabit | Petabyte | Pebibit | Pebibyte |- | Exabit | Exabyte | Exbibit | Exbibyte |- | Zettabit | Zettabyte | — | — |- | Yottabit | Yottabyte | — | — |} :I think all those dinky little stub articles are nonsense which should be eliminated, most of them wouldn't even be worth a "dictionary" entry. They certainly are not encyclopedic. I could see having an article for each prefix, and linking to that. For the rest, one article on Orders of magnitude for bits and for bytes would be more than sufficient--even that's too much IMHO, this article is enough for both. User:Gene Nygaard 17:33, 27 Mar 2005 (UTC) **I agree completely. There is no reason whatever for these quantities to have articles which can never be more than a dictdef. As valid "index entries" they should all redirect here. User:Dpbsmith User_talk:dpbsmith 17:43, 27 Mar 2005 (UTC) ::ARGH! That's what I said in the first place! Talk:Binary prefix#Consolidate all the little articles - User:Omegatron 21:54, Mar 27, 2005 (UTC) :::A good idea. Well spotted. User:Bobblewik User talk:Bobblewik 23:18, 29 Mar 2005 (UTC) ::::Can we please do this soon? See Petabyte#See_also for example. They are just getting bigger. - User:Omegatron 20:29, Apr 3, 2005 (UTC) Alright so almost everyone likes the template idea. Do we have one yet? - User:Omegatron 12:19, May 19, 2005 (UTC) == Vote vote vote! == Opinion poll: Little articles like pebibit keep getting stuff about other units added to them, get altered so they aren't consistent with the others, etc. by anons who probably don't realize there is an article for each individual prefix and unit, like megabit/mebibit/megabyte/mebibyte. So what should we do? === Create a template that links them all to each other and put it in every one === *Support. I'm sure we can all work together to keep the articles to an acceptable consistency, and a template project, along with other minor changes along the way, would be the best way to maintain them without losing information on each article or making this one too central and overpowering. --User:Alexwcovington (User talk:Alexwcovington) 04:47, 19 Apr 2005 (UTC) *Support. Good Idea. I want to find Exabyte or Terabyte if i search for it. --User:Mononoke 09:25, 19 Apr 2005 (UTC) *Support. The template should contain prominent links to Binary prefix, Bit and Byte, and the articles themselves should contain nothing else except a brief definition of the word's meaning(s), and a handful of usage examples. The only exceptions that come to mind are Megabyte and Gigabyte, which have interesting debates about their meanings for floppy and hard disks respectively. – User:Smyth\^{User_talk:Smyth} 16:39, 20 Apr 2005 (UTC) *Support, and I do believe I owe an apology. I deleted most of the merge templates because I found the discussion on Talk:Kilobyte dated June 2004 and I assumed they all dated that far back...then I found the discussion here. What to do? My rationale: **Each article removes the need to link munge (i.e., Binary prefix) since I think it's extremely bad practice **Each article has its own "What links here" and it'd be much easier to see what links to each unit (instead of one page (which is currently limited to 500 max) for all units) **Each article would *explicitly* state what each unit means instead of forcing the visitor to hunt down a table *Again, my apologies on the merge template removal! User:Cburnett 21:45, Apr 20, 2005 (UTC) *:You missed all the kibibit/mebibyte merge entries. :-) - User:Omegatron *Support - This makes sense to me. - User:Omegatron 22:52, Apr 20, 2005 (UTC) === Merge them all into this article or into byte and bit or something like that === *''no votes yet'' === Merge all but kilobyte/megabyte/gigabyte that have significant info on their own === * Support. It's A Good Thing™ that someone finally called for a vote on this. With the present scheme we'd surely be swamped with boring micro-maintenance to keep things consistent at all times. --User:Wernher 05:09, 18 Apr 2005 (UTC) * Support User:Dpbsmith User_talk:dpbsmith 09:57, 18 Apr 2005 (UTC) * kinda support i think it would be a good idea to move the IEC stuff to their corresponding standard prefix pages. there will likely never be more to say about gibli-libbli-bit or whatever silly thing we are calling it than currently is written. i don�t support killing all the articles such as tera which will be growing as time passes on. the template is great and kudos for to the people who wrote this page, its clear and concise. User:Cavebear42 23:41, 19 May 2005 (UTC) === Do nothing === *''no votes yet'' == Onward == It's been a month since that poll was last updated, and there seems to be support for the template idea. (Not a consensus, true.) I've adopted the above table into two: one for -byte pages and one for -bit pages. Table for pebibit, petabit, etc articles: {| style="margin:0 auto; text-align:center;" class="toccolours" ! colspan="3" style="background-color:#ccf;" | Decimal names
powers of ten ! ! colspan="3" style="background-color:#ccf;" | Binary names
powers of two |- ! Name ! Symbol ! Multiple ! ! Name ! Symbol ! Multiple |- | style="text-align:left;" | kilobit | kb | 1 E3 | ≈ | style="text-align:left;" | kibibit | Kib | 2¹⁰ |- | style="text-align:left;" | megabit | Mb | 1 E6 | ≈ | style="text-align:left;" | mebibit | Mib | 2²⁰ |- | style="text-align:left;" | gigabit | Gb | 1 E9 | ≈ | style="text-align:left;" | gibibit | Gib | 2³⁰ |- | style="text-align:left;" | terabit | Tb | 1 E12 | ≈ | style="text-align:left;" | tebibit | Tib | 2⁴⁰ |- | style="text-align:left;" | petabit | Pb | 1 E15 | ≈ | style="text-align:left;" | pebibit | Pib | 2⁵⁰ |- | style="text-align:left;" | exabit | Eb | 1 E18 | ≈ | style="text-align:left;" | exbibit | Eib | 2⁶⁰ |- | style="text-align:left;" | zettabit | Zb | 1 E21 | | | | |- | style="text-align:left;" | yottabit | Yb | 1 E24 | | | | |} Table for petabyte, pebibyte, etc articles: {| style="margin:0 auto; text-align:center;" class="toccolours" ! colspan="3" style="background-color:#ccf;" | Decimal names
powers of ten ! ! colspan="3" style="background-color:#ccf;" | Binary names
powers of two |- ! Name ! Symbol ! Multiple ! ! Name ! Symbol ! Multiple |- | style="text-align:left;" | kilobyte | kB | 1 E3 | ≈ | style="text-align:left;" | kibibyte | KiB | 2¹⁰ |- | style="text-align:left;" | megabyte | MB | 1 E6 | ≈ | style="text-align:left;" | mebibyte | MiB | 2²⁰ |- | style="text-align:left;" | gigabyte | GB | 1 E9 | ≈ | style="text-align:left;" | gibibyte | GiB | 2³⁰ |- | style="text-align:left;" | terabyte | TB | 1 E12 | ≈ | style="text-align:left;" | tebibyte | TiB | 2⁴⁰ |- | style="text-align:left;" | petabyte | PB | 1 E15 | ≈ | style="text-align:left;" | pebibyte | PiB | 2⁵⁰ |- | style="text-align:left;" | exabyte | EB | 1 E18 | ≈ | style="text-align:left;" | exbibyte | EiB | 2⁶⁰ |- | style="text-align:left;" | zettabyte | ZB | 1 E21 | | | | |- | style="text-align:left;" | yottabyte | YB | 1 E24 | | | | |} I suggest that at the bottom of each -bibyte pages we have a ''see also'' with links to: the corresponding decimal-prefixed version, the corresponding -bibit, the binary prefix article, and the orders of magnitude (data) article. Similarly for the -bibit and decimal-prefixed pages. I'll wait for a couple days for comments. If there are no objections, I'll turn the above into real templates and go about changing all the relevant pages. User:One-dimensional Tangent (User talk:One-dimensional Tangent) 19:44, 19 May 2005 (UTC) :Looks good to me. Just one minor point: there is no sense in linking each -bit article to the corresponding -byte, as the two have no connection. :I also suggest that the table headers link to the primary articles, as follows: {| style="margin:0 auto; text-align:center;" class="toccolours" ! colspan="7" style="background-color:#ccf;" | Multiples of bytes |- ! colspan="3" style="background-color:#ddf;" | SI prefix ! ! colspan="3" style="background-color:#ddf;" | Binary prefixes |- ! Name ! Symbol ! Multiple ! ! Name ! Symbol ! Multiple |- | style="text-align:left;" | kilobyte | kB | 1 E3 | ≈ | style="text-align:left;" | kibibyte | KiB | 2¹⁰ |- | style="text-align:left;" | megabyte | MB | 1 E6 | ≈ | style="text-align:left;" | mebibyte | MiB | 2²⁰ |- | style="text-align:left;" | gigabyte | GB | 1 E9 | ≈ | style="text-align:left;" | gibibyte | GiB | 2³⁰ |- | style="text-align:left;" | terabyte | TB | 1 E12 | ≈ | style="text-align:left;" | tebibyte | TiB | 2⁴⁰ |- | style="text-align:left;" | petabyte | PB | 1 E15 | ≈ | style="text-align:left;" | pebibyte | PiB | 2⁵⁰ |- | style="text-align:left;" | exabyte | EB | 1 E18 | ≈ | style="text-align:left;" | exbibyte | EiB | 2⁶⁰ |- | style="text-align:left;" | zettabyte | ZB | 1 E21 | | | | |- | style="text-align:left;" | yottabyte | YB | 1 E24 | | | | |} :And of course, there should be a third template for the bare prefixes, as in #A little better above. :– User:Smyth\^{User_talk:Smyth} 21:19, 19 May 2005 (UTC) :Looks good! I don't think enough people care about this for it to reach a true consensus in the next millenium. I say we just be bold and add it. :I agree that kilobit should link to kilobyte and vice versa. :Where would the third template go, Smyth? - User:Omegatron 21:27, May 19, 2005 (UTC) :: I agree that we won't get a consensus; the reason for the delay was to gather any input others might care to offer. I like the title on Smyth's version, but I'm not sure whether to label the two columns "prefixes", since they show the prefixed words rather than just the prefix. ("Prefixed" perhaps? But that sounds as though something were about to be broken.) User:One-dimensional Tangent (User talk:One-dimensional Tangent) 22:08, 19 May 2005 (UTC) ::Created Template:Quantities of bytes and Template:Quantities of bits. My schedule just changed, so I'm going to start changing pages now. User:One-dimensional Tangent (User talk:One-dimensional Tangent) 22:16, 19 May 2005 (UTC) :::We can always change the titles. I'm just glad we finally got around to doing this. :::By the way, Wikipedia:Naming_conventions_(capitalization) is the first word capitals and then the rest lowercase, so it's "See also", not "See Also". It's absurdly pedantic of me to even bring it up, though. :-) - User:Omegatron 22:59, May 19, 2005 (UTC) ::::Ah. Now I know. Well, I don't feel like changing that now that I'm done, but I'll keep it in mind for future articles. Thanks for pointing that out. :) User:One-dimensional Tangent (User talk:One-dimensional Tangent) 23:05, 19 May 2005 (UTC) Uh oh. Do we need to do the same thing with megabit per second, kibibit per second, etc.? I see everyone is misspelling "mebibit" as "mibibit". - User:Omegatron 23:49, May 23, 2005 (UTC) * See an analogous discussion at Wikipedia:Votes for deletion/Myriametre. User:Uncle G 11:10, 2005 May 24 (UTC) I made another one for the bit rates: Byte rates don't deserve their own articles at this point, and are just merged into bit rates. I would like if someone could double check them all. I fixed a lot of errors, but missed a few I'm sure. For the record, it's mebibit (Mib) and mebibyte (MiB), not mibibyte or MeB. Everyone gets those mixed up. - User:Omegatron 23:11, Jun 19, 2005 (UTC)
== decimal prefixes wrong? == ''Discussion moved from Talk:Gigabyte since it's much more appropriate here. I didn't actually move the whole conversation, since I don't want to overstep anything.'' - User:Omegatron 01:15, May 28, 2005 (UTC) ''I am aware of the errors which people who are pushing the GiB notation (which has not been accepted in widespread use) have put all over the wikipedia. the article on binary prefix is well written for the most part and uses the unpopular titles for the sake of clarity in discussion. there are some claims in there which should be verified such as the ones you have made in the previous comment. please feel free to come forward with proof that those are the accepted uses in those fields (perhaps from IEEE or such) and we can go about citing sources. I have not changed them to the correct uses because i have not done the same. the abstract (such as this article) are easy enough to back up and that is why i edit it. to state what constitutes common use would take more reseach (which i dont currently have time to do) User:Cavebear42 17:20, 23 May 2005 (UTC)'' :That's a very good idea. I'll start collecting references. - User:Omegatron 17:56, May 23, 2005 (UTC) ::And so you did, and a fine job i might add. I added 2 lines below and noted them as mine so as not to confuse the remainder of this work done by User:Omegatron. I think we are settled in data rate issues pretty firmly as being the standad SI interptitations of the units. What I said in Talk:Gigabyte, however, is still true. the original and (from a computer's standpoint) accurate definitions are still very much the standard definition. We can not abandon all that computers are built on and pretend like transistors have 10 fingers. The mebibyte notation has not gained widespread use and we can not pretend as though it has. The standard rule for such things on the wiki is to use the most common usage as used in the world. Also, the Wikipedia:Manual of Style tells us ''"For units of measure use SI units, unless there are compelling historical or pragmatic reasons not to do so"'' and i feel that this is definatly both historical and pragmatic. I am willing join IEEE in conceeding this common usage in the name of clarity and, for lack of other options from IEEE or SI, use the unpopular IEC titles. In order to set a standard to be uniformly implemented across the wiki, I would like to suggest that we create a boilerplate of some sort to explain that we use the less popular titles directing inquisitive readers to this article. I would also like to see us create a rule in the Wikipedia:Manual of Style in order to guide editors. I don't know what it takes to create such rules, but I think that this might be a wise move. perhaps it's time to move this discussion (once again) to Wikipedia talk:Manual of Style? User:Cavebear42 23:36, 31 May 2005 (UTC) :::Actually, I think standards trump common usage. See aluminium. The Wikipedia:Manual of style#Scientific style says "For units of measure use SI units, unless there are compelling historical or pragmatic reasons not to do so". So whether their commonness is a "compelling historical reason" to use them or whether these recommendations even count as standards is debatable. ::''"What I said in Talk:Gigabyte, however, is still true. the original and (from a computer's standpoint) accurate definitions are still very much the standard definition. We can not abandon all that computers are built on and pretend like transistors have 10 fingers."'' :::My biased POV: So the physicists should have their own definition of the mega- prefix so that quoting the speed of light is the more convenient whole number 3 instead of 2.99792458? Or the chemists will come up with their own version of the standard prefixes so that Avogadro's number starts with 6 instead of 6.0221415? The whole point of the SI prefixes is to maintain a consistent set of multipliers so that the various disciplines mesh well together. Laziness on the part of computer engineers shouldn't inconvenience everyone else. - User:Omegatron 13:29, Jun 1, 2005 (UTC) ::Just my 2c since I've been wondering whether to edit this article on the same lines. When measuring bits (or clock cycles), the most common usage appears to be powers of 10 ie. SI. The confusion appears to arise when talking about ''bytes'', whether these should be powers of 10 or powers of 2. Operating systems such as Windows and Linux measure bytes in powers of 2, as do RAM manufacturers. The odd man out seems to be makers of secondary storage devices such as hard disks and USB drives who insist on bytes measured in powers of 10. As far as the manual of style goes, I'd recommend bits are always SI, bytes are always powers of 2. --User:Kudz75 01:04, 1 Jun 2005 (UTC) :::hmmm, where to start? clock cycles would be true. they have very little to do with computers as that it's a measure of time. the measure of time existed before computers and stands independently of computing components. the same would be true for computing terms which done requre computing components such as the gigaflop. these are not derived from a binary system comming out of a transistor or similer device. the case of data rates is interesting. a bit is either 1 or 0 and in that sense, its binary. however data rates dont care about what the data is, they care how much is moved. if you move 100 bits in 1 second, it doesnt matter what those bits were and therefore si units work fine. data storage is where the tables turn. if i have 1 bit of memory, i can store 2 values (0, 1). if i have 2 bits, i can store 4 values (00, 01, 10 , 11). if i have 3 i can store 8 values (000, 001, 010, 011, 100, 101, 110, 111). it is easy to see that this is a 2^x case where x is the number of bits you have. the fact that we break them into bytes and then count them from there is a historical norm, it was once thought that 8 bits could represent any nessicery number/chariter and therefore was the largest nessicery size for data storage. :::as time progressed, we started to make larger devices and used the kilobyte (historical usage) to be 10 bytes of data. this would, of course, store 2¹⁰ different bytes, not 10² differnt bytes. in hindsight, we should ahve found something other to call it than the kilobyte. back then calling it the kibibyte would have us currently not talking about it. the fact that we were already grouping into 8 bits at that time is the reason this is a bytes discussion. you see, if we never went to the 8 bit theory, we would have declared the kilobit (historical useage) to be 2¹⁰ bits. this is why it would be a bad idea to keep the powers of 2 called this confusing tytle in bytes and just not bits (which is what we are pretty much doing now). now, hard drive manufacturers can claim whatever reason they want for using powers of 10 and not powers of 2 but the fact remains that the people who make the drives know the difference and that a drive with ~74 GiB of data has a giant 80GB written on the box. if one drive wrote 74 and another wrote 80 at the same price, you can guess which would sell better. in any case, we count in powers of 10 because we ahve 10 fingers, computers count in powers of 2 because they have 2 states. the confution here came when we chose not to give a new name to this new way of counting. I did not make this decition personally, but it was made and saying that it shouldnt have been doesnt change history. the best we can do a tthis point is figure out how to correct it.User:Cavebear42 18:05, 1 Jun 2005 (UTC) :::IEC prefixes are *not* unpopular. They are gaining widespread use in newly developed applications. The OSes is the main inertia that is holding them back. You are mistaken about the lack of "other options" from IEEE and SI, because both have accepted IEC prefixes years ago. IEEE has published a standard with IEC prefixes, this standard has also been accepted by ANSI which re-released it, and at BIPM it has been decided to insert pointer to IEC prefixes in the upcoming new international SI edition, while American localisation of the current SI edition by NIST has referred to IEC prefixes all along. I have been tracking these issues for years now on my http://members.optus.net/alexey/prefBin.xhtml IEC prefixes and symbols for binary multiples page with links to all relevant documents and software applications that use them. User:Delicates 21:04, 3 Jun 2005 (UTC) ::::perhaps you and i define "popular" diffently, i mean that not only your adverage consumer has never hear of it, i mean that your adverage person who works with electronics and computers on a day to day basis also has never hear of it. that it has been referenced in a document somewhere does not make it popular. I see no point in pointing the finger at OS'es or anything/anyone else. there is a prudent reason why the historical definitions were used. last i heard SI did not have a unit to measure data storage. perhaps they will soon but i havent see that shown. IEEE asked people to not use KB to mean 1024, they did not ask people to use KiB to mean 1024. this is why i said that it was not accepted as their standard. when i get some more time on my hands, ill read your page, it sounds like an interesting thing to track. User:Cavebear42 21:20, 3 Jun 2005 (UTC) :::::IEEE Std 1541-2002, IEEE Trial-Use Standard for prefixes for Binary Multiples is a two-year trial standard that would have ended in 2004. Can't find what happened next. - User:Omegatron 19:36, Jun 6, 2005 (UTC) ::::::It has been accepted into full-use on March 19. User:Delicates 21:50, 6 Jun 2005 (UTC) === Various references === ==== Binary measurements ==== (kilo- = 1024) ===== CDs ===== *[http://www.videohelp.com/forum/userguides/135642.php Data capacity of CDs] - Data capacity in Mb for a CD-ROM **74 min *:= 333,000 sectors * 2048 bytes / sector *:= 681984000 bytes *:= 650.4 Mb **80 min *:= 360,000 sectors * 2048 bytes / sector *:= 737280000 bytes *:= 703.1 Mb (please note that they meant Megabytes (MB) int his article when they said Mb) User:Cavebear42 23:36, 31 May 2005 (UTC) ===== Memory ===== * "As an example, 64 MB of RAM memory always means 64 times 1,048,576 bytes, never 64,000,000." [http://www.dewassoc.com/kbase/hard_drives/binary_v_decimal_measurement.htm] ==== Decimal measurements ==== (kilo- = 1000) ===== DVDs ===== * [http://www.osta.org/technology/pdf/dvdqa.pdf#page=20 Understanding DVD] - Data capacity in GB for a DVD-R ** 2,294,922 sectors * 2048 bytes / sector *:= 4,700,000,000 bytes *:= 4.7 GB ===== Data rates ===== * "Lending confusion to this mess though, in some areas only decimal values are used such as when the term, "56K modem" works at a maximum speed of 56,000 bits per second, not 57,344." [http://www.dewassoc.com/kbase/hard_drives/binary_v_decimal_measurement.htm] * "Just to avoid confusion, 33.6 Kbps = 33600 bps, 28.8 Kbps = 28800 bps (where bps means bits per second), and so on." [http://www.aibn.com/help/FAQ/speed.html] * "Traditionally, Ethernet networks operate at 10 Mega-Bits per Second (10,000,000 Bits per second)" [http://people.morrisville.edu/~drewwe/wireless/glossary.htm] *1.4.48 bit rate (BR): The total number of bits per second transferred to or from the Media Access Control (MAC). For example, 100BASE-T has a bit rate of one hundred million bits per second (10⁸ b/s). [http://standards.ieee.org/getieee802/download/802.3-2002.pdf IEEE 802.3 standard] User:Cavebear42 23:36, 31 May 2005 (UTC) ===== Hard drives ===== * "Drive manufacturers, including Hitachi Global Storage Technologies, market their drive capacities in terms of decimal capacity. In decimal 1 kilobyte (KB) is equal to 1,000 bytes, 1 megabyte (MB) is equal to 1,000,000 bytes, and 1 gigabyte (GB) is equal to 1,000,000,000 bytes. Operating systems and some software programs (fdisk, partitioning utilities, system BIOS, etc�) all view the drive capacity in terms of a binary capacity. In binary, 1KB is equal to 1,024 bytes, 1MB is equal to 1,048,576 bytes, and 1GB is equal to 1,073,741,824 bytes." [http://www.hitachigst.com/hddt/knowtree.nsf/0/5d71892d940d874c86256fcb00774458?OpenDocument Why does my hard drive report a lower capacity than what is on the drive�s label? (Hitachi)] * "Note that the Maximum Capacity shows only 3099 MB instead of 3240 MB. This is because some system BIOSs recognize a Megabyte as 1,048,576 bytes (binary). Drive manufacturers recognize a Megabyte as 1,000,000 bytes (decimal)." [http://www.hitachigst.com/tech/techlib.nsf/techdocs/85256AB8006A31E587256A7D006ED4DB/$file/dtta_diweb.PDF#page=19 Hitachi] * "This has to do with the way nearly every harddrive manufacturer in existance calculates hard drive size. They all define 1 gigabyte = 1,000,000,000 bytes instead of the 1 gigabyte = 1,073,741,824 bytes which it *really* is ... This is standard industry practice" [http://www.techiwarehouse.com/cms/articles.php?cat=11] * "Hard drive size is given in Gigabytes (GB). A Gigabyte is one billion bytes or one billion characters." [http://groups.msn.com/CanadianIdols] * "Hard drive manufacturers define 1 gigabyte as exactly 1,000,000,000 bytes. By their definition, a 45BG hard drive is exactly 45,000,000,000 bytes. The true definition of 1 gigabyte is actually 1,073,741,824 bytes" [http://www.falcon-nw.com/support_faq.asp] ==== Organization recommendations ==== * IEC **Standard: IEC 60027‐2, Second edition, 2000‐11, Letter symbols to be used in electrical technology � Part 2: Telecommunications and electronics ** "These prefixes for binary multiples, which were developed by IEC Technical Committee (TC) 25, Quantities and units, and their letter symbols, with the strong support of the International Committee for Weights and Measures (CIPM) and the Institute of Electrical and Electronics Engineers (IEEE), were adopted by the IEC as Amendment 2 to IEC International Standard IEC 60027-2: Letter symbols to be used in electrical technology - Part 2: Telecommunications and electronics. The full content of Amendment 2, which has a publication date of 1999-01, is reflected in the tables below and the suggestion regarding pronunciation." [http://nedron.net/fom_server/cache/17.html] * IEEE **Standard: IEEE 1541-2002, IEEE Standard for Prefixes for Binary Multiples **[http://www.ieee.org/portal/cms_docs/pubs/transactions/auinfo03.pdf#page=15 Information for authors] - ''"Information for IEEE Transactions, Journals, and Letters Authors"'' ***TABLE OF UNITS AND QUANTITY SYMBOLS ***"mega-: SI prefix for 10⁶. The prefix mega shall not be used to mean 2²⁰ (that is, 1 048 576)." **"Faced with this reality, the IEEE Standards Board decided that IEEE standards will use the conventional, internationally adopted, definitions of the SI prefixes. Mega will mean 1 000 000, except that the base-two definition may be used (if such usage is explicitly pointed out on a case-by-case basis) until such time that prefixes for binary multiples are adopted by an appropriate standards body." [http://physics.nist.gov/cuu/Units/binary.html] (the IEC standard has been published since this note was released and later published by IEEE itself) * NIST ** "The IEC has adopted prefixes for binary multiples in International Standard IEC 60027-2, Second edition, 2000-11, Letter symbols to be used in electrical technology�Part 2: Telecommunications and electronics. ... Although these prefixes are not part of the SI, they should be used in the field of information technology to avoid the incorrect usage of the SI prefixes." [http://physics.nist.gov/Pubs/SP330/sp330.pdf#page=24 Special Publication 330, 2001 Edition] ** "Because the SI prefixes strictly represent powers of 10, they should not be used to represent powers of 2. Thus, one kilobit, or 1 kbit, is 1000 bit and not 2¹⁰ bit = 1024 bit. To alleviate this ambiguity, prefixes for binary multiples have been adopted by the International Electrotechnical Commission (IEC) for use in information technology." [http://physics.nist.gov/cuu/Units/prefixes.html nist.gov] ** "The new prefixes will eliminate the present confusion between powers of 1000 and powers of 1024 since in the field of information technology the SI prefix names and symbols for decimal multiples are now often used to represent binary multiples." [http://nvl.nist.gov/pub/nistpubs/jres/104/2/html/news_briefs/nbrs104-2.htm News briefs Section 1.9] * SI/BIPM ** "These SI prefixes refer strictly to powers of 10. They should not be used to indicate powers of 2 (for example, one kilobit represents 1000 bits and not 1024 bits)." [http://www.bipm.org/utils/en/pdf/si-brochure.pdf#page=23 ] **"A decision was made to include a marginal note discussing the binary multiples along the lines of that given on p.14 of the NIST Special Publication 330, 2001 edition". [[http://www.bipm.org/utils/common/pdf/CCU15.pdf#page=8 Report of the 15th meeting (17 �18 April 2003) to the International Committee for Weights and Measures] * ISO? ** [http://www.gscassociates.com/wg8/edcs/text/unit.html#Table%207.10%20--%20Unit%20Scales%20Dictionary%20for%20powers%20of%20210 ISO/IEC 18025 EDCS units] - Table 7.10 -- Unit Scale Dictionary for powers of 2¹⁰ * ANSI ** Standard: BSR/IEEE 1541-200x, Prefixes for Binary Multiples * W3C **[http://www.w3.org/TR/2003/NOTE-mathml-units-20031110/#prefix Units in MathML] - Section 5.3.5 -- Prefix, and Appendix B -- shows how to incorporate IEC prefixes into mathematical markup. ==Comment in the article== ''Warning: These values are wrong, SI uses 10-based counting, not 2-based. SEC (below) is 2-based. This also seems formatted quite messily (spaces everywhere).'' Comments to the article like that belong here. Or fix the article if you think its wrong. --User:Kudz75 06:26, 30 May 2005 (UTC) Added again by User:66.231.16.111 as a HTML comment - User:Omegatron 19:28, May 30, 2005 (UTC) ''non standard usage? i noted a warning about this being incorrect, and i commented on the spaces used for formatting, but i mreant around the table headings (" Symbol " or " Value ") ... not the numerical seperator used for reading clarity. the original author says SI kilo for bytes is 2^10 = 1024, that's the SEC KiB (noted below). SI kB or KB is 10^3 = 1000 ... hard disk manufactorers say "1 GB = 1 000 000 000 bytes" because they use SI numbering ... or 10 based counting, which is what SI is for, not base 2 counting, which SEC does. I added this as a comment this time so that i don't pollute the document, but I didn't know who to take this to'' == new table == I think the new table "Approximate ratios between binary prefixes and their decimal equivalent" should be folded into the preexisting tables. ("> 10⁹ (7.4% error)" and so on) - User:Omegatron 14:22, Jun 6, 2005 (UTC) == Nominal 1.44 MB floppies and Windows XP == I've rewritten some text on the 1000*1024 hybrid "megabyte" used e.g. in floppies. This text was quite properly restored by User:Smyth after deletion by an anon. I just checked http://www.cdw.com and as of 2005 every vendor still refers to the standard floppy as nominally 1.44 MB. Now, as for Windows XP, the situation is curioser and curioser. I was going to put something in the article but changed my mind pending any rational explanation of what Windows XP is doing. As of the last time I tried, which was five minutes ago: when formatting a 3.5" floppy, Windows XP's formatting utility designates the diskette and the formatting operation as :3.5" 1.44MB 512 bytes/sector That is, ''Windows XP still uses 1.44MB as the nominal capacity of a floppy.'' But, after formatting, Properties reports the "capacity" :1457664 bytes 1.38 MB (which is exactly 2847 sectors BTW... and only 1.4235 "hybrid" 1024000 megabytes, not 1.44, so obviously this is the usable capacity after the overhead of the FAT directory is deducted). Now, 1457664 / 1024 / 1024 = 1.39014 MiB. That is, the second value is NOT consistent with MB meaning MiB, and cannot be explained as roundoff error since the fraction BOTH rounds AND truncates to 1.39 MiB, not 1.38 MiB. Sounds like some kind of unaccountable sloppiness on Microsoft's part. I can come up with the following wild-ass guess. Suppose there was some point in the code's history in which the code computed 1457664 / 1024 / 1000 = 1.4235 hybrid "megabytes." Now suppose that for some reason that was arbitrarily truncated to 1.42 MB for display. Now suppose someone came along and decided that it should be displayed in 1024 * 1024-byte "MB." Now suppose that instead of fixing the calculation they slapped on a correction. Now suppose that for some reason they based the correction on 1.42 rather than 1.4235. 1.42 * 1000 / 1024 = 1.3867 Finally, suppose for some utterly unaccountable reason they decided to truncate rather than round... well, I guess you could get 1.38. Given that all of the intermediate values in the appropriate calculations can be expressed EXACTLY in binary fractions OR decimals OR floating point with a very reasonable number of decimal places, this would seem to suggest sloppiness. Yes, I remember the days when computers were still occasionally used for ''computing'' and programmers were expected to know the ''rudiments'' of mathematics and numerical analysis. Just hand me that slide rule, Sonny, and some carbon paper to put in my IBM Selectric. User:Dpbsmith User_talk:dpbsmith 13:18, 21 Jun 2005 (UTC) :Oh, you must have missed the announcement. Computing isn't about math or accuracy anymore. It's now about obfuscated code and Leet. - User:Omegatron 14:01, Jun 21, 2005 (UTC)

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