HOME

TheInfoList



OR:

Giga ( or ) is a
unit prefix 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 ...
in the
metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Intern ...
denoting a factor of a
short-scale The long and short scales are two of several naming systems for integer powers of ten which use some of the same terms for different magnitudes. For whole numbers smaller than 1,000,000,000 (109), such as one thousand or one million, the ...
billion or long-scale milliard (109 or ). It has the symbol G. ''Giga'' is derived from the
Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...
word (''gígas''), meaning "
giant In folklore, giants (from Ancient Greek: ''gigas'', cognate giga-) are beings of human-like appearance, but are at times prodigious in size and strength or bear an otherwise notable appearance. The word ''giant'' is first attested in 1297 fr ...
". The ''
Oxford English Dictionary The ''Oxford English Dictionary'' (''OED'') is the first and foundational historical dictionary of the English language, published by Oxford University Press (OUP). It traces the historical development of the English language, providing a c ...
'' reports the earliest written use of ''giga'' in this sense to be in the Reports of the
IUPAC The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is ...
14th Conférence Internationale de Chimie in 1947: "The following prefixes to abbreviations for the names of units should be used: G giga 109×." When referring to information units in
computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, ...
, such as
gigabyte 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. This definit ...
, giga may sometimes mean (230); this causes ambiguity.
Standards organization A standards organization, standards body, standards developing organization (SDO), or standards setting organization (SSO) is an organization whose primary function is developing, coordinating, promulgating, revising, amending, reissuing, interpr ...
s discourage this and use giga- to refer to 109 in this context too.NIST Guide for the Use of the International System of Units (Appendix D. ref 5)
/ref> ''Gigabit'' is only rarely used with the binary interpretation of the prefix. The
binary prefix A binary prefix is a unit prefix for multiples of units. It is most often used in data processing, data transmission, and digital information, principally in association with the bit and the byte, to indicate multiplication by a power  ...
'' gibi'' has been adopted for 230, while reserving ''giga'' exclusively for the metric definition.


Pronunciation

In
English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ...
, the prefix ''giga'' can be pronounced (a hard ''g'' as in ''giggle''), or (a soft ''g'' as in ''gigantic'', which shares ''giga'' Ancient Greek root). A prominent example of this latter pronunciation is found in the pronunciation of ''gigawatts'' in the 1985 film ''
Back to the Future ''Back to the Future'' is a 1985 American science fiction film directed by Robert Zemeckis, and written by Zemeckis and Bob Gale. It stars Michael J. Fox, Christopher Lloyd, Lea Thompson, Crispin Glover, and Thomas F. Wilson. Set in 1985, ...
''. According to the American writer Kevin Self, a German committee member of the
International Electrotechnical Commission The International Electrotechnical Commission (IEC; in French: ''Commission électrotechnique internationale'') is an international standards organization that prepares and publishes international standards for all electrical, electronic and ...
proposed ''giga'' as a prefix for 109 in the 1920s, drawing on a verse (evidently "Anto-logie") by the German humorous poet Christian Morgenstern that appeared in the third (1908) edition of his (Gallows Songs). This suggests that a hard German was originally intended as the pronunciation. Self was unable to ascertain when the (soft ''g'') pronunciation came into occasional use, but claimed that as of 1995 it had returned to (hard ''g''). In 1998, a poll by the phonetician John C. Wells found that 84% of Britons preferred the pronunciation of ''gigabyte'' starting with (as in ''gig''), 9% with (as in ''jig''), 6% with (''guy''), and 1% with (as in ''giant'').Wells, J. C. (1998).
LPD pronunciation preference poll 1998
'.


Common usage

*
gigahertz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...
clock rate In computing, the clock rate or clock speed typically refers to the frequency at which the clock generator of a processor can generate pulses, which are used to synchronize the operations of its components, and is used as an indicator of the pr ...
of a
CPU A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, a ...
, for instance, 3 GHz = *
gigabit The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represented ...
bandwidth of a
network Network, networking and networked may refer to: Science and technology * Network theory, the study of graphs as a representation of relations between discrete objects * Network science, an academic field that studies complex networks Mathematic ...
link, for instance, 1 Gbit/s = . *
gigabyte 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. This definit ...
—for instance, for
hard disk A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magn ...
capacity, 120 GB = ; * gigayear or
gigaannum A year or annus is the orbital period of a planetary body, for example, the Earth, moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the h ...
—one billion (109) years, sometimes abbreviated Gyr, but the preferred usage is Ga.


Binary prefix

The notation can represent 1,073,741,824 (230) bytes or 1,000,000,000 bytes. Under the IEC 60027-2 A.2 and ISO/IEC 80000 standards, the correct notation of 230 is '' gibi'' (symbol Gi). distinction So one
gibibyte The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable uni ...
() is 1,073,741,824 bytes or . Despite international standards, the use of = 230 B is widespread. A laptop advertised as having has 8,589,934,592 bytes of memory: , or .


See also

*
Binary prefix A binary prefix is a unit prefix for multiples of units. It is most often used in data processing, data transmission, and digital information, principally in association with the bit and the byte, to indicate multiplication by a power  ...
*
Gigabit Ethernet In computer networking, Gigabit Ethernet (GbE or 1 GigE) is the term applied to transmitting Ethernet frames at a rate of a gigabit per second. The most popular variant, 1000BASE-T, is defined by the IEEE 802.3ab standard. It came into use ...
*
SI prefix The International System of Units, known by the international abbreviation SI in all languages and sometimes pleonastically as the SI system, is the modern form of the metric system and the world's most widely used system of measurement. ...
* List of commonly used taxonomic affixes *
RKM code The RKM code, also referred to as "letter and numeral code for resistance and capacitance values and tolerances", "letter and digit code for resistance and capacitance values and tolerances", or informally as "R notation" is a notation to speci ...


References


External links

{{wiktionary, giga-
BIPM website
SI prefixes he:תחיליות במערכת היחידות הבינלאומית#גיגה