Kibibyte

Last updated
Multiples of bytes
Decimal
Value Metric
1B byte
1000kB kilobyte
10002MB megabyte
10003GB gigabyte
10004TB terabyte
10005PB petabyte
10006EB exabyte
10007ZB zettabyte
10008YB yottabyte
Binary
Value IEC JEDEC
1B byte Bbyte
1024KiB kibibyte KBkilobyte
10242MiB mebibyte MBmegabyte
10243GiB gibibyte GBgigabyte
10244TiB tebibyte
10245PiB pebibyte
10246EiB exbibyte
10247ZiB zebibyte
10248YiB yobibyte

The kibibyte is a multiple of the unit byte for digital information. [1] The binary prefix kibi means 210, or 1024; therefore, 1 kibibyte is 1024 bytes. The unit symbol for the kibibyte is KiB.

Contents

The unit was established by the International Electrotechnical Commission (IEC) in 1998, [2] has been accepted for use by all major standards organizations, and is part of the International System of Quantities. [3] The kibibyte was designed to replace the kilobyte in those computer science contexts in which the term kilobyte is used to mean 1024 bytes. The interpretation of kilobyte to denote 1024 bytes, conflicting with the SI definition of the prefix kilo (1000), used to be common. [4]

Definition

The unit prefix kibi specifies multiplication by 210 (1024). It was derived as a portmanteau from the words kilo and binary, indicating its origin in the closeness in value to the SI prefix kilo (1000). While the SI prefix is written with lowercase (k), all IEC binary prefixes start with an uppercase letter. [5]

Therefore, the definition of the kibibyte is:

1 kibibyte (KiB) = 210 bytes = 1024 bytes.

The next larger unit of information in the sequence with IEC binary prefixes is the mebibyte (MiB) (220 bytes):

1024 kibibytes = 1 mebibyte.

IEC specification 80000-13 defines one byte as 8 bits (1 B = 8 bit). Therefore,

1 kibibyte = 8192 bits.

History

The kibibyte is closely related to the kilobyte, which equals 1000 bytes, as the prefix kilo is defined in the International System of Units. The kibibyte was established by the International Electrotechnical Commission (IEC) in 1998, [2]

Prior to the definition of the binary prefixes, the kilobyte generally represented 1024 bytes in most fields of computer science, but was sometimes used to mean exactly one thousand bytes. When describing random access memory, it typically meant 1024 bytes, but when describing disk drive storage, it meant 1000bytes. [6] The errors associated with this ambiguity are relatively small (2.4%).

In 1995, the International Union of Pure and Applied Chemistry's Interdivisional Committee on Nomenclature and Symbols attempted to resolve this ambiguity by proposing a set of binary prefixes for the powers of 1024. [7] [8] After adopting the proposal, the IEC published the standard in January 1999. [9] [10]

In 1999, Donald Knuth suggested calling the kibibyte a "large kilobyte" (KKB). [11]

Despite the formal adoption of the kibibyte, kilobyte continued to often be used to mean 1024 bytes as late as 2007 in some product advertising and other contexts. [12] [13] [14]

See also

Related Research Articles

A binary prefix is a unit prefix for multiples of units in data processing, data transmission, and digital information, notably the bit and the byte, to indicate multiplication by a power of 2.

The gigabyte is a multiple of the unit byte for digital information. The prefix giga means 109 in the International System of Units (SI). Therefore, one gigabyte is one billion bytes. The unit symbol for the gigabyte is GB.

Giga ( or ) is a unit prefix in the metric system denoting a factor of a short-scale billion or long-scale milliard (109 or 1000000000). It has the symbol G.

The kilobyte is a multiple of the unit byte for digital information.

Kilo is a decimal unit prefix in the metric system denoting multiplication by one thousand (103). It is used in the International System of Units, where it has the symbol k, in lower case.

The kilobit is a multiple of the unit bit for digital information or computer storage. The prefix kilo- (symbol k) is defined in the International System of Units (SI) as a multiplier of 103 (1 thousand), and therefore,

The megabyte is a multiple of the unit byte for digital information. Its recommended unit symbol is MB. The unit prefix mega is a multiplier of 1000000 (106) in the International System of Units (SI). Therefore, one megabyte is one million bytes of information. This definition has been incorporated into the International System of Quantities.

The mebibyte is a multiple of the unit byte for digital information. The binary prefix mebi means 220; therefore one mebibyte is equal to 1048576bytes, i.e., 1024 kibibytes. The unit symbol for the mebibyte is MiB.

The gibibyte is a multiple of the unit byte for digital information. The binary prefix gibi means 230, therefore one gibibyte is equal to 1073741824bytes = 1024 mebibytes. The unit symbol for the gibibyte is GiB. It is one of the units with binary prefixes defined by the International Electrotechnical Commission (IEC) in 1998.

The tebibyte is a multiple of the unit byte for digital information. It is a member of the set of units with binary prefixes defined by the International Electrotechnical Commission (IEC). Its unit symbol is TiB.

The megabit is a multiple of the unit

  1. [[]] bit for digital information. The prefix mega (symbol M) is defined in the International System of Units (SI) as a multiplier of 106 (1 million), and therefore

The pebibyte is a multiple of the unit byte for digital information. It is a member of the set of units with binary prefixes defined by the International Electrotechnical Commission (IEC). Its unit symbol is PiB.

IEC 60027 is a technical international standard for letter symbols published by the International Electrotechnical Commission, comprising the following parts:

The kibibit is a multiple of the bit, a unit of digital information storage, using the standard binary prefix kibi, which has the symbol Ki, meaning 210. The unit symbol of the kibibit is Kibit.

The mebibit is a multiple of the bit, a unit of information, prefixed by the standards-based multiplier "mebi" (symbol Mi), a binary prefix meaning 220. The unit symbol of the mebibit is Mibit.

A unit prefix is a specifier or mnemonic that is prepended to units of measurement to indicate multiples or fractions of the units. Units of various sizes are commonly formed by the use of such prefixes. The prefixes of the metric system, such as kilo and milli, represent multiplication by powers of ten. In information technology it is common to use binary prefixes, which are based on powers of two. Historically, many prefixes have been used or proposed by various sources, but only a narrow set has been recognised by standards organisations.

IEEE 1541-2002 is a standard issued in 2002 by the Institute of Electrical and Electronics Engineers (IEEE) concerning the use of prefixes for binary multiples of units of measurement related to digital electronics and computing.

ISO 80000 or IEC 80000 is an international standard developed and promulgated jointly by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC).

The JEDEC memory standards are the specifications for semiconductor memory circuits and similar storage devices promulgated by the Joint Electron Device Engineering Council (JEDEC) Solid State Technology Association, a semiconductor trade and engineering standardization organization.

In telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multiples of bits per second (bit/s) and bytes per second (B/s). For example, the data rates of modern residential high-speed Internet connections are commonly expressed in megabits per second (Mbit/s).

References

  1. International Electrotechnical Commission (2007). "Prefixes for binary multiples" . Retrieved 2014-01-09.
  2. 1 2 International Electrotechnical Commission (January 1999), IEC 60027-2 Amendment 2: Letter symbols to be used in electrical technology - Part 2: Telecommunications and electronics
  3. "IEC 80000-13:2008". International Organization for Standardization . Retrieved 2013-07-21.
  4. "Definitions of the SI units: The binary prefixes". physics.nist.gov. Retrieved 2018-04-09.
  5. National Institute of Standards and Technology. "Prefixes for binary multiples" . Retrieved 2015-10-09.
  6. NIST "Prefixes for binary multiples" https://physics.nist.gov/cuu/Units/binary.html
  7. IUCr 1995 Report - IUPAC Interdivisional Committee on Nomenclature and Symbols (IDCNS) http://ww1.iucr.org/iucr-top/cexec/rep95/idcns.htm
  8. "Binary Prefix" University of Auckland Department of Computer Science https://wiki.cs.auckland.ac.nz/stageonewiki/index.php/Binary_prefix
  9. NIST "Prefixes for binary multiples" https://physics.nist.gov/cuu/Units/binary.html
  10. Amendment 2 to IEC International Standard IEC 60027-2: Letter symbols to be used in electrical technology - Part 2: Telecommunications and electronics.
  11. "What is a kilobyte?" . Retrieved 2010-05-20.
  12. "Safier vs WDC complaint". WesternDigital.com. Archived from the original on October 16, 2007. Retrieved 2007-11-15.
  13. Grainger, Brian (7 August 2005). "I've got a bigger gigabyte than you!". Independent Computer Products Users Group (ICPUG). Retrieved 2007-11-15.
  14. Barry Wittman; Aditya Mathur; Tim Korb (30 December 2012). Start Concurrent: An Introduction to Problem Solving in Java with a Focus on Concurrency, 2013 Edition. Purdue University Press. p. 5. ISBN   978-1-55753-672-3 . Retrieved 1 May 2013.