1790s
1793
* The French ''Commission temporaire de Poids & Mesures rêpublicaines'', ''Décrets de la Convention Nationale'', proposes the binary prefixes ''1795
*The prefixes ''1870s
* Metric prefix established in 1873.1930s
* Metric prefixes "1940s
1943–1944
* J. W. Tukey coins the word "bit" as an abbreviation of "binary digit".1947
* "The Whirlwind I Computer is planned with a storage capacity of 2,048 numbers of 16 binary digits each."1948
* Tukey's "bit" is referenced in the work of information theorist1950s
* In the 1950s, "1 kilobit" meant 1000 bits: ** "In the '50s, amazingly enough—and only total coincidence—I actually was given the job of writing the operational specifications ..for what was called cross telling. They handed me this thing and said, 'You're going to define how the hand-over process works between direction centers', ..and I had no idea what they were talking about. But we had ..one-kilobit lines connecting the direction centers and I thought, 'Good God! 1,000 bits a second. Well, we'll surely be able to figure out something to do with that. — Saverah Warenstein, former programmer at Lincoln Laboratory, IBM1952
* The first1955
* The1956
* The1957
* The1958
* "64 million (226) bytes" is used in a memo by Dr.1959
* The term 32k is used in print to refer to a memory size of 32768 (215). ** The author is with the Westinghouse Electric Corporation.1960s
1960
* The 11th ''Conférence Générale des Poids et Mesures'' (1955–1961
* A search of the Computer History Museum's Stretch collection of 931 text documents dated from September 1955 through September 1961 shows no usage of k or K to describe main storage size.1961
* ** Quoted in OED as first instance of "kilobit", though "it is more usual" suggests it is already in common use (see timeline entry for 1957) * Described device contains 512 words, 24 bits each (=12,288 bits) * "It is no longer reasonable to spend as much time to transmit an 80 bit address as 12 kilobits of message information-a 1500 to 1 ratio.... We have theoretically and experimentally proved that speech can be compressed from the straightforward requirement for 48 kilobit PCM channel capability to 2400 bits by the application of the Dudley syllabic vocoder." * The1962
* A reference to a "4k IBM 1401" meant 4,000 characters of storage (memory).1963
* Ludwig uses kilobit in the decimal sense * DEC Serial Drum Type 24 ** "Drums are equipped to store either 64, 128, or 256 data blocks, providing a memory capability of 16384, 32768, or 65536 computer words" (no abbreviations) *1964
* Gene Amdahl's seminal April 1964 article on1965
* "Each IBM 2315 disk cartridge can hold the equivalent of more than one million characters of information. * "One method of designing a slave memory for instructions is as follows. Suppose that the main memory has 64K words (where K=1024) and, therefore, 16 address bits, and that the slave memory has 32 words and, therefore, 5 address bits." * IBM 1620 CPU Model 1 (a decimal machine) System Reference Library, dated 19 July 1965, states: ** "A core storage module, which is 20,000 addressable positions of magnetic core storage, is located in the 1620. Two additional modules are available ... Each core storage module (20,000 positions) is made up of 12 core planes as shown in Figure 3. Each core plane contains all cores for a specific bit value."1966
* CONTIGUOUS BULK STORAGE ADDRESSING is filed on 3 January 1966 ** "Note that 'K' as used herein indicates 'thousands.' Each storage location in the present embodiment includes 64 data bits and 8 related parity bits, as described herein." ** "Thus, if only storage unit 1A were provided, it would contain addresses 0 through 32K; storage IB would include addresses between 32K and 64K, storage 2A would contain addresses between 64K and 96K, ..."1968
* A Univac 9400 disc based computer system ... "can have 2–8 8411 drives for 14.5–58 megabytes capacity. The 8411 has a transfer rate of 156K bytes per second." using megabytes in a decimal sense * Donald Morrison proposes to use the Greek letter kappa (" κ") to denote 1024 bytes, to denote 1024×1024, and so on. (At the time, memory size was small, and only 'K' was in widespread use.) *1969
*1970s
1970
* "The following are excerpts from an IBM Data Processing Division press technical fact sheet distributed on 30 June 1970. ** Users of the Model 165 will have a choice of five main core storage sizes, ranging from 512,000 to over 3-million bytes. Seven main memory sizes are available for the Model 155, ranging from 256,000 to over 2-million bytes." * "Each of the five system/360 model 75 computers (Fig. 2) has one megabyte of primary core storage plus four megabytes of large core storage (LCS, IBM 2361)."1971
* IBM System/360 Operating System: Storage Estimates, uses K in a binary sense approximately 450 times, such as ""System/360 Configuration: Model 40 with 64K bytes of storage and storage protection." Note the letter "K" is also sometimes used as a variable in this document (see page 23).1972
* Lin and Mattson introduce the term Mbyte. **1973
* ** OCEANPORT, N.J., SEPT. 25, 1973 – A 16-bit minicomputer priced at under $2,000.00 in quantities and a 32-bit minicomputer priced at under $6,000.00 in quantities were introduced today by Interdata, Inc. The 16-bit mini, the Model 7/16, includes an 8KB memory unit in its basic configuration, and will be available for delivery in the first quarter of 1974. The single unit price of the 7/16 is $3,200.00. The 32-bit mini, the Model 7/32, includes a 32KB memory unit and will be available for delivery in the second quarter of 1974. The single unit price of the 7/32 is $9,950.00. * DEC PDP-11/40 Manual ** "Direct addressing of 32K 16-bit words or 64K 8-bit bytes (K = 1024)" (Page 1-1) Contrast the 1969 PDP-11 Handbook, which avoids this usage almost everywhere. (Above)1974
*The seminal 1974 Winchester HDD article which makes extensive use of Mbytes with M being used in the conventional, 106 sense. Arguably all of today's HDD's derive from this technology. * The October 19741975
* The 15th CGPM defines the1976
* DEC RK05/RK05J/RK05F disk drive maintenance manual ** "Bit Capacities (unformatted)" "25 million" , "50 million" (57,600 bits/ track * 406 , 812 tracks = 23,385,600 , 46,771,200 bits) * The Memorex 1976 annual report has 10 instances of the use of megabyte to describe storage devices and media. * Caleus Model 206-306 Maintenance Manual uses 3MB to characterize a drive having 3,060,000 bytes capacity. * The first 5 inch floppy disk drive, the Shugart SA 400, is introduced in August 1976. The drive had 35 tracks and was single sided. The data sheet gives the unformatted capacity as 3125 bytes per track for a total of 109.4 Kbytes (3125 × 35 = 109,375). When formatted with 256 byte sectors and 10 sectors per track the capacity is 89.6 Kbytes (256 × 10 × 35 = 89,600).1977
* HP 7905A Disc Drive Operator's Manual ** "nearly 15 million bytes" with no other abbreviations * 1977 Disk/Trend Report – Rigid Disk Drives, published June 1977 ** This first edition of the annual report on the hard disk drive industry makes extensive use of MB as 106 bytes. The industry, in 1977, is segmented into nine segments ranging from "Disk Cartridge Drives, up to 12 MB" to "Fixed Disk Drives, over 200 MB." While the categories changed during the next 22 years of publication, Disk/Trend, the principal marketing study of the hard disk drive industry always and consistently categorized the industry in segments using prefixes M and later G in the decimal sense. * VAX-11/780 Architecture Handbook 1977–78. Copyright 1977 Digital Equipment Corporation. ** Page 2-1 "physical address space of 1 gigabyte (30 bits of address)" The initial hardware was limited to 2 M bytes of memory utilizing the 4K MOS RAM chips. The VAX11/780 handbooks use M byte and Mbyte in the same paragraph.1978
* DEC RM02/03 Adapter Technical Description Manual ** "The RM02 or RM03 Disk Drive (Figure 1-1) is an 80M byte (unformatted; 67M byte formatted) ... storage device ... in the 16-bit format, the maximum storage capacity is 33,710,080 data words per disk pack" (33,710,080 * 16/8 = 67,420,160 8-bit bytes)1979
*1980s
1980
*1981
*1982
* Brochure for the1983
* IBM S/360 S/370 Principles Of Operation GA22-7000 includes as statement: ** "In this publication, the letters K, M and G denote the multipliers 210, 220 and 230 respectively. Although the letters are borrowed from the decimal system and stand for kilo 103, mega 106 and giga 109 they do not have decimal meaning but instead present the power of 2 closest to the corresponding power of 10." * IBM 341 4-inch Diskette Drive ** unformatted capacity "358,087 bytes" ** "Total unformatted capacity (in kilobytes): 358.0" *1984
* The Macintosh Operating System is the earliest known operating system using the prefix K in a binary sense to report memory size and HDD capacity. ** In the original 1984 Apple Macintosh ad, page 8, Apple characterized its 3 floppy disk as "400K," that is, 800×512 byte sectors or 409,600 bytes = 400 KiB. Similarly, the February 19841985
* Exabyte Corp. founded * September 1985. Apple introduced Macintosh Finder 5.0 with HFS (Hierarchical File System)along with the Mac's first hard drive, the Hard Disk 20. Finder 5.x displayed drive capacity in binary K units. The Hard Disk 20 Manual specified the HDD as having ** "Data capacity (formatted): 20,769,280 bytes ** Bytes per block: 532 (512 user data, 20 system data) ** Total disk blocks: 39,040 * and has the following definition in its glossary:1986
*1987
* Seagate Universal Installation Handbook ** ST125 listed as 21 "Megabytes" formatted capacity, later document seems to confirm that this is decimal * Disk/Trend Report – Rigid Disk Drives, October 1987 ** First use of GB in a decimal sense in this HDD marketing survey; Figure 1 states "FIXED DISK DRIVES more than 1 GB" market size as $10,786.6 million. * Webster's Ninth New Collegiate Dictionary (1987) has binary definitions for kilobyte and megabyte. ** kilobyte ''n'' 10) is the power of 2 closest to 1000">rom the fact that 1024 (210) is the power of 2 closest to 1000(1970): 1024 bytes ** megabyte ''n'' (1970): 1,048,576 bytes1988
* Imprimis Wren VII 5 Inch Rigid Disk Drive Data Sheet, printed 11/88 ** "Capacity of 1.2 gigabyte (GB)"1989
* IBM1990s
1990
* Matsuda et al refer to 1024 bits (32x32 optoelectronic switches) as "1-kb memory". * GEOS ad ** "512K of memory" * The enhanced1991
* The 19th CGPM defines the%@FILESIZE '...''
), taking special arguments to control the format of the returned values: The lowercase letters ''k'' and ''m'' are used as decimal prefixes, whereas the uppercase letters ''K'' and ''M'' are used in their binary meaning.
1993
* While the HP 48G calculators are labelled ''32K'' or ''128K'' to describe their built-in SRAM capacity in a binary sense, the user manual variably uses the terms ''KB'', ''KBytes'' and ''kilobytes'' in the same meaning./ ''min'',''max''/code> for file selection, recognizing lowercase letters ''k'' and ''m'' as decimal prefixes and uppercase letters ''K'' and ''M'' as binary prefixes.
1994
* Feb: Microsoft
Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washi ...
Windows for Workgroup 3.11 File Manager
A file manager or file browser is a computer program that provides a user interface to manage files and folders. The most common operations performed on files or groups of files include creating, opening (e.g. viewing, playing, editing or pr ...
uses MB in a binary sense to describe HDD capacity. Prior versions of Windows only used K in a binary sense to describe HDD capacity.
* Micropolis 4410 Disk Drive Information
** "1,052 MB Formatted Capacity"
** "Unformatted Per Drive 1,205 MB" (133.85 MB per surface, 9 read-write heads)
* The HP 200LX
The HP 200LX Palmtop PC (F1060A, F1061A, F1216A), also known as project ''Felix'', is a personal digital assistant introduced by Hewlett-Packard in August 1994. It was often called a Palmtop PC, and it was notable that it was, with some m ...
models use "1MB"/"2MB"/"4MB" in a binary sense to describe their RAM capacity.
1995
* August: The International Union of Pure and Applied Chemistry
The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is ...
's Interdivisional Committee on Nomenclature and Symbols proposed new prefixes kibi (symbol Ki), mebi (Mi), gibi (Gi) and tebi (Ti), etc for powers of 1024.
1996
* FOLDOC
The Free On-line Dictionary of Computing (FOLDOC) is an online, searchable, encyclopedic dictionary of computing subjects.
History
FOLDOC was founded in 1985 by Denis Howe and was hosted by Imperial College London. In May 2015, the site was up ...
defines the exabyte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable uni ...
(1 EB) as 1024 petabyte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable uni ...
s (1024 PB), with petabyte used in the binary sense of 10245 B.
* Markus Kuhn proposes a system with ''di'' prefixes, like the "dikilobyte" (K2B) and "digigabyte" (G2B). It did not see significant adoption.
1997
* January: Bruce Barrow endorses the International Union of Pure and Applied Chemistry
The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is ...
's proposal for prefixes kibi, mebi, gibi, etc in "A Lesson in Megabytes" in IEEE Standards Bearer
* IEEE requires prefixes to take the standard SI meaning (e.g., mega always to mean 10002). Exceptions for binary meaning (mega to mean 10242) are permitted as an interim measure (where pointed out on a case by case basis) until a binary prefix could be standardised.
* FOLDOC defines the zettabyte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable uni ...
(1 ZB) as 1024 exabytes (1024 EB) and the yottabyte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable uni ...
(1 YB) as 1024 zettabytes (1024 ZB).
1998
* December: IEC
The International Electrotechnical Commission (IEC; in French: ''Commission électrotechnique internationale'') is an international standards organization that prepares and publishes international standards for all electrical, electronic and r ...
establishes unambiguous prefixes for binary multiples (KiB
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...
, MiB
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...
, GiB, TiB, PiB and EiB), reserving kB, MB, GB and so on for their decimal sense. Formally published in January 1999.
1999
* Donald Knuth
Donald Ervin Knuth ( ; born January 10, 1938) is an American computer scientist, mathematician, and professor emeritus at Stanford University. He is the 1974 recipient of the ACM Turing Award, informally considered the Nobel Prize of computer sc ...
, who uses decimal notation like 1 MB = 1000 kB, expresses "astonishment" that the proposal was adopted by the IEC, calling them "funny-sounding", and proposes that the powers of 1024 be designated as "large kilobytes" and "large megabytes" (abbreviated KKB and MMB, as "doubling the letter connotes both binary-ness and large-ness"). Double prefixes were formerly used in the metric system, however, with a multiplicative meaning ("MMB" would be equivalent to "TB"), and this proposed usage never gained any traction.
* In their November 1999 paper, Steven W. Schlosser, John Linwood Griffin, David F. Nagle and Gregory R. Ganger adopt the symbol GiB for gibibyte and quote data throughput in mebibytes per second
** "... Although these numbers appear to yield a capacity of 2.98 GiB per sled, the capacity decreases ... This yields an effective capacity of about 2.098 GiB per sled. ..."
** "maximum throughput (MiB/s)"
* The IEEE 802.11-1999 standard introduces the binary time unit TU defined as 1024 μs (10-6 Kis).
2000s
2001
* IBM, z/Architecture
z/Architecture, initially and briefly called ESA Modal Extensions (ESAME), is IBM's 64-bit complex instruction set computer (CISC) instruction set architecture, implemented by its mainframe computers. IBM introduced its first z/Architect ...
, Reference Summary
** Page 59, list the power of 2 and 16, and their decimal value. There is a column name 'Symbol', which list K (kilo), M (mega), G (giga), T (tera), P (peta) and E (exa) for the power of 2 of, respectively, 10, 20, 30, 40, 50, 60.
* Peuhkuri adopts IEC prefixes in his paper at the 2001 Internet Measurement Conference: "... allows maximum size of 224 that requires 1 GiB of RAM ... or acknowledgement numer icis within 32 KiB range. ... on a PC with Celeron processor with 512 MiB of memory ..."
* The Linux kernel
The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU ...
uses IEC prefixes.
2002
* Marcus Kuhn introduces the term kibihertz to mean 1024 Hz.
** "Most embedded clocks (state of the art is still a calibrated 32 kibihertz crystal) have a frequency error of at least 10^-5 (10 ppm), and therefore drift away from the TAI rate faster than 1 second per week."
Mackenzie et al 2002
** use tebibyte (TiB), pebibyte (PiB), exbibyte (EiB)
** use the symbols ZiB, YiB, accompanied by notes explaining that these are "a GNU extension to IEC 60027-2"
2003
* The World Wide Web Consortium publishes a Working Group Note describing how to incorporate IEC prefixes into mathematical markup.
2004
*2004 revision of IEEE Standard Letter Symbols for Units of Measurement (SI Units, Customary Inch-Pound Units, and Certain Other Units), IEEE Std 260.1, incorporates IEC definitions for KiB, MiB etc, reserving the symbols kB, MB etc for their decimal counterparts.
2005
* IEC extends binary prefixes to include zebi (Zi) and yobi (Yi)
*IEC prefixes are adopted by the IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operati ...
after a two-year trial period.
**On March 19, 2005 the IEEE standard IEEE 1541-2002 (Prefixes for Binary Multiples) was elevated to a full-use standard by the IEEE Standards Association after a two-year trial period.
2006
* The BIPM
The International Bureau of Weights and Measures (french: Bureau international des poids et mesures, BIPM) is an intergovernmental organisation, through which its 59 member-states act together on measurement standards in four areas: chemistr ...
publishes the 8th SI Brochure including the note
*:"These SI prefixes refer strictly to powers of 10. They should not be used to indicate powers of 2 .. The IEC has adopted prefixes for binary powers .. 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."
* In addition to the ''k'' and ''m'' decimal as well as the ''K'' and ''M'' binary prefixes, 4DOS 7.50.141 (2006-12-24) adds support for ''g'' and ''G'' as decimal respective binary prefixes in variable functions and size range parameters.
2007
*Windows Vista
Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...
still uses the binary conventions (e.g., 1 KB = 1024 bytes, 1 MB = 1048576 bytes) for file and drive sizes, and for data rates
*GParted
GParted (acronym of GNOME Partition Editor) is a GTK front-end to GNU Parted and an official GNOME partition-editing application (alongside Disks). GParted is used for creating, deleting, resizing, moving, checking, and copying disk partitio ...
uses IEC prefixes for partition sizes
*Advanced Packaging Tool
Advanced package tool, or APT, is a free-software user interface that works with core libraries to handle the installation and removal of software on Debian, and Debian-based Linux distributions. APT simplifies the process of managing softwa ...
and Synaptic Package Manager use standard SI prefixes for file sizes
* IBM uses "exabyte" to mean 10246 bytes. "Each address space, called a 64-bit address space, is 16 exabytes (EB) in size; an exabyte is slightly more than one billion gigabytes. The new address space has logically 264 addresses. It is 8 billion times the size of the former 2-gigabyte address space, or 18,446,744,073,709,600,000 bytes."
2008
* The US National Institute of Standards and Technology
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical s ...
guidelines require use of IEC prefixes KiB, MiB ... (and not kB, MB) for binary byte multiples
**p. 29, "The names and symbols for the prefixes corresponding to 210, 220, 230, 240, 250, and 260 are, respectively: kibi, Ki; mebi, Mi; gibi, Gi; tebi, Ti; pebi, Pi; and exbi, Ei. Thus, for example, one kibibyte is also written as 1 KiB = 2 10 B = 1024 B, where B denotes the unit ''byte''. Although these prefixes are not part of the SI, they should be used in the field of information technology to avoid the non-standard usage of the SI prefixes."
* The binary prefixes are defined in IEC Standard IEC 80000-13
ISO 80000 or IEC 80000 is an international standard introducing the International System of Quantities (ISQ).
It was developed and promulgated jointly by the International Organization for Standardization (ISO) and the International Electrotec ...
, formally incorporating them into the ISO/IEC series of standards of quantities and units.
*IBM WebSphere
IBM WebSphere refers to a brand of proprietary computer software products in the genre of enterprise software known as "application and integration middleware". These software products are used by end-users to create and integrate applications ...
describes data transfer using unambiguous IEC prefixes
** "The name of the file currently being transferred. The part of the individual file that has already been transferred is displayed in B, KiB, MiB, GiB, or TiB along with total size of the file in parentheses. The unit of measurement displayed depends on the size of the file. B is bytes per second. KiB/s is kibibytes per second, where 1 kibibyte equals 1024 bytes. MiB/s is mebibytes per second, where 1 mebibyte equals 1 048 576 bytes. GiB/s is gibibytes per second where 1 gibibyte equals 1 073 741 824 bytes. TiB/s is tebibytes per second where 1 tebibyte equals 1 099 511 627 776 bytes."
:::* "The rate the file is being transferred in KiB/s (kibibytes per second, where 1 kibibyte equals 1024 bytes.)"
2009
* Apple Inc. uses the SI decimal definitions for capacity (e.g., 1 kilobyte = 1000 bytes) in the Mac OS X v10.6 operating system to conform with standards body recommendations and avoid conflict with hard drive manufacturers' specifications.
* Frank Löffler and co-workers report disk size and computer memory in tebibytes.
**"For the largest simulations using 2048 cores this sums up to about 650 GiB per complete checkpoint and about 6.4 TiB in total (for 10 checkpoints)."
* the SourceForge web site
** "For example, in 2009, the SourceForge web site reported file sizes using binary prefixes for several months before changing back to SI prefixes but switching the file sizes to powers of ten."
* The binary prefixes, as defined by IEC 80000-13, are incorporated into ISO 80000-1, including a note that "SI prefixes refer strictly to powers of 10, and should not be used for powers of 2." In ISO 80000-1, the application of the binary prefixes is not limited to computer technology. For example, 1 KiHz = 1024 Hz.
2010s
2010
* The Ubuntu operating system uses the SI prefixes for base-10 numbers and IEC prefixes for base-2 numbers as of the 10.10 release.
* Baba Arimilli and co-workers use the pebibyte (PiB) for computer memory and disk storage and exbibyte (EiB) for archival storage
** "Blue Waters will comprise more than 300.000 POWER7 cores, more than 1 PiB memory, more than 10 PiB disk storage, more than 0.5 EiB archival storage, and achieve around 10 PF/s peak performance."
* HP publishes a leaflet explaining use of SI and binary prefixes "To reduce confusion, vendors are pursuing one of two remedies: they are changing SI prefixes to the new binary prefixes, or they are recalculating the numbers as powers of ten."
** "For disk and file capacities, the latter remedy is more popular because it is much easier to recognize that 300 GB is the same as 300,000 MB than to recognize that 279.4 GiB is the same as 286,102 MiB."
** "For memory capacities, binary prefixes are more natural. For example, reporting a Smart Array controller cache size of 512 MiB is preferable to reporting it as 536.9 MB."
** "HP is considering modifying its storage utilities to report disk capacity with correct decimal and binary values side-by-side (for example, '300 GB (279.4 GiB)'), and report cache sizes with binary prefixes ('1 GiB')."
2011
* The GNU operating system
GNU () is an extensive collection of free software (383 packages as of January 2022), which can be used as an operating system or can be used in parts with other operating systems. The use of the completed GNU tools led to the family of operat ...
uses the SI prefixes for base-10 numbers and IEC prefixes for base-2 numbers as of the parted-2.4 release (May 2011).
** "specifying partition start or end values using MiB, GiB, etc. suffixes now makes parted do what I want, i.e., use that precise value, and not some other that is up to 500KiB or 500MiB away from what I specified. Before, to get that behavior, you would have had to use carefully chosen values with units of bytes ('B') or sectors ('s') to obtain the same result, and with sectors, your usage would not be portable between devices with varying sector sizes. This change does not affect how parted handles suffixes like KB, MB, GB, etc."
** "Note that as of parted-2.4, when you specify start and/or end values using IEC binary units like 'MiB', 'GiB', 'TiB', etc., parted treats those values as exact, and equivalent to the same number specified in bytes (i.e., with the 'B' suffix), in that it provides no 'helpful' range of sloppiness. Contrast that with a partition start request of '4GB', which may actually resolve to some sector up to 500MB before or after that point. Thus, when creating a partition, you should prefer to specify units of bytes ('B'), sectors ('s'), or IEC binary units like 'MiB', but not 'MB', 'GB', etc."
* On its Archive Project Request Form, the University of Oxford
, mottoeng = The Lord is my light
, established =
, endowment = £6.1 billion (including colleges) (2019)
, budget = £2.145 billion (2019–20)
, chancellor ...
uses IEC prefixes: "The initial amount of data to be archived ( MiB GiB TiB )"
* The IBM Style Guide permits IEC prefixes or "SI prefixes" if used consistently and explained to the user "Whether you choose to use IEC prefixes for powers of 2 and SI prefixes for powers of 10, or use SI prefixes for a dual purpose ... be consistent in your usage and explain to the user your adopted system."
2012
* June: Toshiba describes data transfer rates in units of MiB/s. In the same Press Release, SSD storage capacity is given in decimal gigabytes, accompanied by the footnote "One Gigabyte (GB) means 109 = 1,000,000,000 bytes using powers of 10. A computer operating system, however, reports storage capacity using powers of 2 for the definition of 1 GB = 1,073,741,824 bytes and therefore shows less storage capacity"
* July: Ola BRUSET and Tor Øyvind VEDAL are granted a patent citing the binary unit KiHz to mean 1024 hertz
* The Minnesota Supercomputing Institute of the University of Minnesota
The University of Minnesota, formally the University of Minnesota, Twin Cities, (UMN Twin Cities, the U of M, or Minnesota) is a public land-grant research university in the Twin Cities of Minneapolis and Saint Paul, Minnesota, United States. ...
uses IEC prefixes to describe its supercomputing facilities
** "Itasca is an HP Linux cluster with 1,091 HP ProLiant BL280c G6 blade servers, each with two quad-core 2.8 GHz Intel Xeon X5560 'Nehalem EP' processors sharing 24 GiB of system memory, with a 40-gigabit QDR InfiniBand (IB) interconnect. In total, Itasca consists of 8,728 compute cores and 24 TiB of main memory."
** "Cascade consists of a Dell R710 head/login node, 48 GiB of memory; eight Dell compute nodes, each with dual X5675 six-core 3.06 GHz processors and 96 GiB of main memory; and 32 Nvidia M2070 GPGPUs. A compute node is connected to four GPGPUs, each of which has 448 3.13 GHz cores and 5 GiB of memory. Each GPU is capable of 1.2 single-precision TFLOPS and 0.5 double-precision TFLOPs."
* Phidgets Inc describes PhidgetSBC3 as a "Single board computer running Debian 7.0 with 128 MiB DDR2 SDRAM, 1 GiB Flash, integrated 1018 and 6 USB 2.0 High Speed 480Mbits/s ports".
* IBM's Customer Information Center uses IEC prefixes to disambiguate
** "To reduce the possibility of confusion, this information center represents data storage using both decimal and binary units. Data storage values are displayed using the following format:#### decimal unit (binary unit). By this example, the value 512 terabytes is displayed as: 512 TB (465.6 TiB)"
2013
* February: Toshiba distinguishes unambiguously between decimal and binary prefixes by means of footnotes. Hybrid drives MQ01ABD100H and MQ01ABD075H are described as having a buffer size of 32 MiB.
** "1 MB (megabytes) = 1,000,000 bytes, 1 GB (gigabytes) = 1,000,000,000 bytes, 1 TB (terabytes) = 1,000,000,000,000 bytes"
** "KiB (kebibytes ic = 1,024 (210 bytes), MiB (mebibytes) = 1,048,576 (220) bytes, GiB (gibibytes) = 1,073,741,824 (230) bytes".
*March: Kevin Klughart uses the zebibyte (ZiB) and yobibyte (YiB) as units for maximum volume size
* PRACE Best Practice Guide uses IEC prefixes for net capacity (300 TiB) and throughput (2 GiB/s).
* Nicla Andersson, of Sweden's National Supercomputer Centre, Sweden, refers to the NSC's Triolith as having "42.75 TiB memory" and "75 TiB/s aggregate memory BW" and to a 2018 DARPA
The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military.
Originally known as the A ...
target of "32–64 PiB memory"
* August: Mitsuo Yokokawa, of Kobe University
, also known in the Kansai region as , is a leading Japanese national university located in the city of Kobe, in Hyōgo. It was established in 1949, but the academic origins of Kobe University trace back to the establishment of Kobe Higher Comme ...
, describes the Japanese K Computer as having "1.27 (1.34) PiB" of memory.
* The official file server of the University of Stuttgart
The University of Stuttgart (german: Universität Stuttgart) is a leading research university located in Stuttgart, Germany. It was founded in 1829 and is organized into 10 faculties. It is one of the oldest technical universities in Germany wi ...
reports file sizes in gibibytes (GiB) and tebibytes (TiB).
* In their book ''IBM Virtualization Engine TS7700 with R3.0'', Coyne et al use IEC prefixes to distinguish them from decimal prefixes. Examples are
** "Larger, 1.1 GB (1 GiB) internal buffer on Model E06/EU6, 536.9 MB (512 MiB) for Model E05, 134.2 MB (128 MiB) for Model J1A"
** "Up to 160 Mibit/sec. native data rate for the Models E06 and EU6, four times faster than the model J1A at 40 Mibit/sec. (Up to 100 Mibit/sec. for the Model E05)"
Maple 17
uses MiB and GiB as units of memory usage.
* November: The online computer dictionary FOLDOC defines the megabyte as one million (10002) bytes.
2014
* February: Rahul Bali writes
** "the equia (IBM)contains in total 1,572,864 processor cores with 1.5 PiB memory"
** "The total CPU plus coprocessor memory f the Tianhe-2 (NUDT)is 1,375 TiB."
* CDBurnerXP states disc sizes in mebibytes (MiB) and gibibytes (GiB), clarifying that "in Windows, if you see GB or MB it usually refers to GiB or MiB respectively".
* September: HP 3PAR StoreServ Storage best practices guide uses binary prefixes for storage and decimal prefixes for speed.
2019
*The BIPM
The International Bureau of Weights and Measures (french: Bureau international des poids et mesures, BIPM) is an intergovernmental organisation, through which its 59 member-states act together on measurement standards in four areas: chemistr ...
publishes the 9th SI brochure, confirming the position from its 8th brochure (published in 2006), with the note
*:"The SI prefixes refer strictly to powers of 10. They should not be used to indicate powers of 2 ..
2020s
2020
* A Californian court finds that, as the NIST
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical sci ...
specifies that prefixes such as "G" are decimal rather than binary, and that California law specifies that the NIST definitions of measure "shall govern ... transactions in this state", and because the vendor of a 64 GB flash drive with 64 billion bytes indicated on the packaging of the drive that 1 GB = 1,000,000,000 bytes, they did not deceive consumers into believing that the drive had 64×1024×1024×1024 bytes.
2021
* Ainslie, Halvorsen and Robinson point out the parallel with the confusion between a one-third octave
A one-third octave is a logarithmic unit of frequency ratio equal to either one third of an octave (1200/3 = 400 cents: major third) or one tenth of a decade (3986.31/10 = 398.631 cents: M3 ). An alternative (unambiguous) term for one tenth o ...
and a one-tenth decade in acoustics.
*: "The near coincidence between ten octaves and three decades (210 ≈ 103) is identical to the one that causes confusion in the computer industry by use of the term “kilobyte” to mean 1024 B ... when the internationally accepted use of the prefix kilo requires it to mean 1000 B."
2022
*November: The additional decimal prefixes '' ronna-'' for 10009 and ''quetta-
A metric prefix is a unit prefix that precedes a basic unit of measure to indicate a multiple or submultiple of the unit. All metric prefixes used today are decadic. Each prefix has a unique symbol that is prepended to any unit symbol. The pre ...
'' for 100010 were adopted by the International Bureau of Weights and Measures
The International Bureau of Weights and Measures (french: Bureau international des poids et mesures, BIPM) is an intergovernmental organisation, through which its 59 member-states act together on measurement standards in four areas: chemistry ...
(BIPM). Binary counterparts to ''ronna-'' and ''quetta-'' were suggested in a consultation paper of the International Committee for Weights and Measures
The General Conference on Weights and Measures (GCWM; french: Conférence générale des poids et mesures, CGPM) is the supreme authority of the International Bureau of Weights and Measures (BIPM), the intergovernmental organization established i ...
' Consultative Committee for Units (CCU) as '' robi-'' (Ri, 10249) and '' quebi-'' (Qi, 102410), but so far they have not been adopted by the IEC or ISO. (1+4 pages)
References
{{DEFAULTSORT:Timeline Of Binary Prefixes
B
Units of information