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.
Pronunciation
The accepted English pronunciation of the initial G of giga was once soft, /ˈdʒaɪgə/ (like gigantic), but now the pronunciation with a hard G, /ˈgɪgə/ (like giggle), is significantly more common. However, both pronunciations are likely to be understood by most English speakers, though the second is likely to be preferred. As example of the soft g sound is found in the 1985 movie Back to the Future, where gigawatts was pronounced like jigawatts. This was before units like gigabyte were commonly used.
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
- Gigabit — bandwidth of a network, e.g. 1 Gbit = 1 000 000 000 bit/s
| Prefix | Base 10 | Decimal | Adoption [nb 1] | |
|---|---|---|---|---|
| Name | Symbol | |||
| quetta | Q | 1030 | 1000000000000000000000000000000 | 2022[1] |
| ronna | R | 1027 | 1000000000000000000000000000 | |
| yotta | Y | 1024 | 1000000000000000000000000 | 1991 |
| zetta | Z | 1021 | 1000000000000000000000 | |
| exa | E | 1018 | 1000000000000000000 | 1975[2] |
| peta | P | 1015 | 1000000000000000 | |
| tera | T | 1012 | 1000000000000 | 1960 |
| giga | G | 109 | 1000000000 | |
| mega | M | 106 | 1000000 | 1873 |
| kilo | k | 103 | 1000 | 1795 |
| hecto | h | 102 | 100 | |
| deca | da | 101 | 10 | |
| — | — | 100 | 1 | — |
| deci | d | 10−1 | 0.1 | 1795 |
| centi | c | 10−2 | 0.01 | |
| milli | m | 10−3 | 0.001 | |
| micro | μ | 10−6 | 0.000001 | 1873 |
| nano | n | 10−9 | 0.000000001 | 1960 |
| pico | p | 10−12 | 0.000000000001 | |
| femto | f | 10−15 | 0.000000000000001 | 1964 |
| atto | a | 10−18 | 0.000000000000000001 | |
| zepto | z | 10−21 | 0.000000000000000000001 | 1991 |
| yocto | y | 10−24 | 0.000000000000000000000001 | |
| ronto | r | 10−27 | 0.000000000000000000000000001 | 2022[1] |
| quecto | q | 10−30 | 0.000000000000000000000000000001 | |
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See also
External links
- ^ a b "On the extension of the range of SI prefixes". 18 November 2022. Retrieved 5 February 2023.
- ^ "Metric (SI) Prefixes". NIST.