What is microsecond? - Definition from WhatIs.com
Part of the Computing fundamentals glossary:

(This definition follows U.S. usage in which a billion is a thousand million and a trillion is a 1 followed by 12 zeros.)

A microsecond (us or Greek letter mu plus s) is one millionth (10 -6 ) of a second.

For comparison, a millisecond (ms or msec) is one thousandth of a second and is commonly used in measuring the time to read to or write from a hard disk or a CD-ROM player or to measure packet travel time on the Internet.

A nanosecond (ns or nsec) is one billionth (10 -9 ) of a second and is a common measurement of read or write access time to random access memory ( RAM ).

A picosecond is one trillionth (10 -12 ) of a second, or one millionth of a microsecond.

A femtosecond is one millionth of a nanosecond or 10 -15 of a second and is a measurement sometimes used in laser technology.

An attosecond is one quintillionth (10 -18 ) of a second and is a term used in photon research.

This was last updated in August 2007
Posted by: Margaret Rouse

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