The speed of the processor is measured with the clock frequency. The processor consistently works internally at the same clock frequency. The IBM PC has a clock frequency of 4.77 MHz (Megahertz). Compatibles sometimes use higher frequencies, but higher speeds may create compatibility problems.
CLOCK SPEED
Meaning of CLOCK SPEED in English
Jensen's Technology English Glossary. Английский словарь фирмы Jensen Technologies. 2012