Giga

From Freepedia

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.

Contents 1 Pronunciation 2 Common usage 3 See also 4 External links

Pronunciation

The accepted English pronunciation of the initial G of giga was once soft, /ˈdʒaɪgə/ (like gigantic), but now the hard pronunciation, /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

SI prefixes

10n	Prefix	Symbol	Short scale	Long scale	Decimal equivalent
1024	yotta	Y	Septillion	Quadrillion	1 000 000 000 000 000 000 000 000
1021	zetta	Z	Sextillion	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
100	none	none	One		1
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

• SI prefix
• Binary prefix
• gibibyte
• Gigabit Ethernet

1 kilo byte (kB)	<math>2^{10}</math> Byte
1 mega byte (MB)	<math>2^{20}</math> Byte
1 giga byte (GB)	<math>2^{30}</math> Byte
1 terra byte (TB)	<math>2^{40}</math> Byte
and so on.

External links

• BIPM website