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Kibibyte

A Kibibyte is 1024 bytes. “Kibibyte” is a more accurate word for what has been traditionally articulated in modern computing as “kilobyte.”

According to Système International (SI) standards, use of “Kilobyte” (1,000) to designate an exponent of 2 (1024 = 210) has always been a misuse of the term, leading to confusion.

Formally: “Kibibyte” is a multiple of the unit byte for quantities of digital information. The binary prefix kibi, a contraction of "kilo-, binary [equivalent]," denotes the base-ten number 1024, the round binary number closest to 1000; therefore, 1 kibibyte is 1024bytes. The unit symbol for the kibibyte is KiB.[1] The unit was established by the International Electrotechnical Commission (IEC) in 1999[2] and has been accepted for use by all major standards organizations. The term "Kibibyte" has seen little adoption outside the computer industry as yet, but the use is growing. [3][4][5][6]

Multiples of bytes
SI decimal prefixesBinary
usage		IEC binary prefixes
Name
(Symbol)		ValueName
(Symbol)		Value
kilobyte (kB)103210kibibyte (KiB)210
megabyte (MB)106220mebibyte (MiB)220
gigabyte (GB)109230gibibyte (GiB)230
terabyte (TB)1012240tebibyte (TiB)240
petabyte (PB)1015250pebibyte (PiB)250
exabyte (EB)1018260exbibyte (EiB)260
zettabyte (ZB)1021270zebibyte (ZiB)270
yottabyte (YB)1024280yobibyte (YiB)280
See also: Multiples of bits · Orders of magnitude of data

Contents

Definition

1 kibibyte = 210 bytes = 1024 bytes.

The prefix kibi is derived as a portmanteau of 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), the IEC prefix starts with an uppercase letter.

History

The kibibyte is closely related to the kilobyte. The latter is often used in some contexts as a synonym for the kibibyte, but formally refers to 103 bytes = 1000 bytes, as the prefix is defined in the International System of Units.

The binary interpretation of the metric prefixes causes relatively small differences with the smallest prefixes in the series, i.e. for kilo and mega, but grows to substantial differences beyond (see binary prefix: deviation between powers of 1024 and powers of 1000).

In Introduction to MMIX, Donald Knuth proposed that this unit be called a large kilobyte (abbreviated KKB).[7] Other early proposals included using the Greek lowercase letter κ (kappa) for 1024 bytes (and using k exclusively for 1000), bK, KB, and others. See binary prefix: early suggestions.

Adoption of the binary prefixes has been limited, primarily being used in open source software. In most cases, the kilobyte continues to be used to refer to a power of ten as well as a power of two.[8][9]

See also

References

  1. ^ International Electrotechnical Commission (2007). "Prefixes for binary multiples". http://www.iec.ch/zone/si/si_bytes.ht m. Retrieved 2007-05-06.
  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. ^ Upgrading and Repairing PCs, Scott Mueller, Pg. 596, ISBN 0-7897-2974-1
  4. ^ The silicon web: physics for the Internet age, Michael G. Raymer, Pg. 40, ISBN 978-1-4398-0311-0
  5. ^ Knuth: Recent News. Cs-staff.stanford.edu. Retrieved on 2011-01-07.
  6. ^ Atwood, Jeff. (2007-09-10) Gigabyte: Decimal vs. Binary. Coding Horror. Retrieved on 2011-01-07.
  7. ^ "What is a kilobyte?". http://www-cs-faculty.stanford.edu/~u no/news99.html. Retrieved 2010-05-20.
  8. ^ "Safier vs WDC complaint". http://www.wdc.com/settlement/docs/co mplaint.htm. Retrieved 2007-11-15.
  9. ^ Rowlett, Brian (7 August 2005). "I've got a bigger gigabyte than you!". Independent Computer Products Users Group (ICPUG). http://www.icpug.org.uk/national/feat ures/050807fe.htm. Retrieved 2007-11-15.
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