See also: Timeline of binary prefixes Main memory Įarly computers used one of two addressing methods to access the system memory binary (base 2) or decimal (base 10). 4.3.7 Data transmission and clock rates.3.4 Other standards bodies and organizations.2.1 Deviation between powers of 1024 and powers of 1000.1.4 Standardization of dual definitions.1.3 Information transfer and clock rates.In 2008, the IEC prefixes were incorporated into the International System of Quantities alongside the decimal prefixes of the international standard system of units (see ISO/IEC 80000). Accordingly, the US National Institute of Standards and Technology (NIST) requires that SI prefixes only be used in the decimal sense: kilobyte and megabyte denote one thousand bytes and one million bytes respectively (consistent with SI), while new terms such as kibibyte, mebibyte, and gibibyte, having the symbols KiB, MiB, and GiB, denote 1024 bytes, 1 048 576 bytes, and 1 073 741 824 bytes, respectively. Starting around 1998, the International Electrotechnical Commission (IEC) and several other standards and trade organizations addressed the ambiguity by publishing standards and recommendations for a set of binary prefixes that refer exclusively to powers of 1024. The use of the same unit prefixes with two different meanings has caused confusion. In contrast with the binary prefix usage, this use is described as a decimal prefix, as 1000 is a power of 10 (10 3). For example, a 500 gigabyte hard disk holds 500 000 000 000 bytes, and a 1 Gbit/s (gigabit per second) Ethernet connection transfers data at nominal speed of 1 000 000 000 bit/s. In most other contexts, the industry uses the multipliers kilo, mega, giga, etc., in a manner consistent with their meaning in the International System of Units (SI), namely as powers of 1000. As this is a power of 1024, and 1024 is a power of two (2 10), this usage is referred to as a binary measurement. In citations of main memory ( RAM) capacity, gigabyte customarily means 1 073 741 824 bytes. The computer industry has historically used the units kilobyte, megabyte, and gigabyte, and the corresponding symbols KB, MB, and GB, in at least two slightly different measurement systems.
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.
0 kommentar(er)
