Online Encyclopedia
Giga
Giga (symbol: G) is a prefix in the SI system of units denoting 109, or 1 000 000 000.
Confirmed in 1960, it comes from the Greek γίγας, meaning giant.
In computing, giga can sometimes mean 1 073 741 824 (230) for information units, eg gigabit or gigabyte, but can also denote 1 000 000 000 of other quantities, e.g. transfer rates: 1 gigabit/s = 1 000 000 000 bit/s. The binary prefix gibi has been suggested for 230, to resolve this ambiguity, but had yet to achieve widespread usage.
In speech, gigabyte is often abbreviated to gig, as in "This is a ten-gig hard drive". The initial G in giga- is usually pronounced hard as in geek, not soft as in giant. However, in the 1985 movie Back to the Future, the term giga was pronounced with a soft g sound, as jiga, in the word gigawatts. This was before units like gigabyte were commonplace.
Common usage
- Gigabyte — hard disk capacity, e.g. 120 Gb; DVD capacity, e.g. 5 Gb = 5 × 1 073 741 824 bytes.
- Gigahertz — clock rate of a CPU, e.g. 3 GHz = 3 000 000 000 Hz
10n | Prefix | Symbol | Short scale | Long scale Name | Decimal Equivalent |
---|---|---|---|---|---|
1024 | yotta | Y | Septillion | Quadrillion | 1 000 000 000 000 000 000 000 000 |
1021 | zetta | Z | Censored page | Trilliard (thousand trillion) | 1 000 000 000 000 000 000 000 |
1018 | exa | E | Quintillion | Trillion | 1 000 000 000 000 000 000 |
1015 | peta | P | Quadrillion | Billiard (thousand billion) | 1 000 000 000 000 000 |
1012 | tera | T | Trillion | Billion | 1 000 000 000 000 |
109 | giga | G | Billion | Milliard (thousand million) | 1 000 000 000 |
106 | mega | M | Million | 1 000 000 | |
103 | kilo | k | Thousand | 1 000 | |
102 | hecto | h | Hundred | 100 | |
101 | deca, deka | da | Ten | 10 | |
10−1 | deci | d | Tenth | 0.1 | |
10−2 | centi | c | Hundredth | 0.01 | |
10−3 | milli | m | Thousandth | 0.001 | |
10−6 | micro | µ | Millionth | 0.000 001 | |
10−9 | nano | n | Billionth | Milliardth | 0.000 000 001 |
10−12 | pico | p | Trillionth | Billionth | 0.000 000 000 001 |
10−15 | femto | f | Quadrillionth | Billiardth | 0.000 000 000 000 001 |
10−18 | atto | a | Quintillionth | Trillionth | 0.000 000 000 000 000 001 |
10−21 | zepto | z | Sextillionth | Trilliardth | 0.000 000 000 000 000 000 001 |
10−24 | yocto | y | Septillionth | Quadrillionth | 0.000 000 000 000 000 000 000 001 |
See also
External link
- Conversion of bits and bytes http://www.sengpielaudio.com/calculator-bits.htm
- BIPM website http://www.bipm.org