The clock speed in a computer is a measure of how many calculations a computer's processor makes in a second. This is measured as a frequency in varying levels of hertz (Hz), or cycles per second.

The clock speed of a computer's processor is one of the main determining factors in a computer's speed and computing power.

Common Clock Speeds
The various levels of clock speed are commonly quoted as megahertz, or million cycles per second, and gigahertz, a billion cycles/s.

History
The clock speed in a personal computer has gone from the Intel 486's mere megahertz in 1989 to the multigigahertz processors of today.

Considerations
To measure a computer's swiftness, you must consider not only clock speed but the speed and amount of RAM and speed of the system bus.