Mega Code Archive

Measurement Units (New Standards)

Title: Measurement Units (New Standards) Question: Few are aware that the IEC approved a new standard for names and symbols for use in the fields of data processing and data transmission. Answer: Due to the binary nature of computers, data size and capacity is measured in multiples of 1024 or 2^(10). For reasons we will probably never know entirely, the computer world began using the metric prefix kilo to represent 1024, when it truly means 1000. This of course was only the beginning of something that would soon turn into a much more confusing issue for the world around, leading to incompatibility in standards and in implemented systems. Example: depending on the area of work, its application, and who you are talking to, a megabyte now represents differing numbers of bytes. For most it is 1,048,576, for others it is 10.6, and others still it is 1,024,000. Due to the misuse of the term kilo and the overall lack of standardization, in December 1998 the International Electrotechnical Commission (IEC), the leading international organization for worldwide standardization in electrotechnology, set out to correct this by approving, as an IEC International Standard, names and symbols for prefixes for binary multiples for use in the fields of data processing and data transmission. The standard was adopted in January 1999 by the Institute of Electrical and Electronics Engineers (IEEE). As a result, kilobyte, megabyte and gigabyte should now be used to express the decimal multiples of 1000, 1,000,000 and 1,000,000,000 bytes, instead of the binary multiples. To represent the binary multiples, a set of new terms have been created: kibibyte, mebibyte and gibibyte. These new terms should now be used to express the binary multiples of 1024, 1,048,576 and 1,073,741,824 bytes. These new prefixes are formed using the first two letters of the metric prefixes plus bi (short for binary). The new abbreviations are KiB, MiB, GiB, and TiB. Using the new system, we would have a gibibyte of 2.30 bytes and a gigabyte of 10.9 bytes, and the 3-1/2 inch diskette would be formatted for 1440 KiB. A small glossary of new terms Kilobyte(KB): a unit of measure consisting of 1000 bytes. Kilobit(Kb): a unit of measure consisting of 1000 bits. Kibibyte(KiB): a unit of measure consisting of 1024 bytes. References IEC: http://www.iec.ch IEEE: http://www.ieee.org