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Kibibyte

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A kibibyte (a contraction of kilo binary byte, pronounced KEE-bee-byte) is a unit of information or computer storage, established by the International Electrotechnical Commission in 2000. Its symbol is KiB.[1] It was designed to replace the "kilobyte" in computer science, when used to mean 1024 bytes, which conflicts with the SI definition of the prefix "kilo".

1 kibibyte = 210 bytes = 1,024 bytes

The kibibyte is closely related to the kilobyte, which can be used either as a synonym for kibibyte or to refer to 103 bytes = 1,000 bytes (see binary prefix).

Usage of these terms is intended to avoid the confusion, common in describing storage media, as to the ambiguous meaning of "kilobyte". Thus the term kibibyte has been defined to refer exclusively to 1,024 bytes.

The confusion if kilobyte is used to refer to both 1,000 and 1,024 bytes became more substantial when hard drives grew to gigabyte and larger units. If one expects power-of-two values to refer to capacity, and manufacturers use power-of-ten values, the difference could be substantial. With a kilobyte (1,024 versus 1,000), the difference is 2.4%. With the megabyte (1,024² or 1,048,576, versus 1,000,000) the percentage difference becomes 4.9%. With "gigabytes", if one uses 1024³, the size of a drive would be expected to be 1,073,741,824 bytes per gigabyte versus a mere 1,000,000,000 — a difference of 7.4%.

Confusion can be compounded by the use of both 1,024 and 1,000 in a single definition. The quoted capacity of 3½ inch HD floppy disks is 1.44 MB, where MB stands for 1000 times 1024 bytes. The total capacity is thus 1,474,560 bytes, or approximately 1.41 MiB.

Adoption

Adoption of this term has been limited. In most cases the "kilo" prefix is used even if the meaning is a power of two. The most common usage is for just K on its own as a unit rather than a muliplier prefix, where 1K equals 1024 bytes. This is rarely confused in context with the unit of temperature Kelvin.[2][3][4][5]

See also

Multiple-byte units
Decimal
Value Metric
1000 kB kilobyte
10002 MB megabyte
10003 GB gigabyte
10004 TB terabyte
10005 PB petabyte
10006 EB exabyte
10007 ZB zettabyte
10008 YB yottabyte
10009 RB ronnabyte
100010 QB quettabyte
Binary
Value IEC Memory
1024 KiB kibibyte KB kilobyte
10242 MiB mebibyte MB megabyte
10243 GiB gibibyte GB gigabyte
10244 TiB tebibyte TB terabyte
10245 PiB pebibyte
10246 EiB exbibyte
10247 ZiB zebibyte
10248 YiB yobibyte
10249
102410
Orders of magnitude of data

Notes

  1. ^ International Electrotechnical Commission (2007). "Prefixes for binary multiples". Retrieved 2007-05-06.
  2. ^ "Safier vs WDC complaint". Retrieved 2007-11-15.
  3. ^ Rowlett, Prof. Russ (April 16, 2005). "Metric Prefixes". University of North Carolina at Chapel Hill. Retrieved 2007-11-15.
  4. ^ Simpson, Rick. "Prefixes for binary multiples". Rice University. Retrieved 2007-11-15.
  5. ^ Grainger, Brian (7 August, 2005). "I've got a bigger gigabyte than you!". Independent Computer Products Users Group (ICPUG). Retrieved 2007-11-15. {{cite web}}: Check date values in: |date= (help)