4.77 MHz and 10 MHz are examples of

Concept

Clock speed (clock frequency) is the rate at which a CPU's internal clock generates pulses that synchronise its operations. It is measured in hertz and its multiples — kilohertz (kHz), megahertz (MHz) and gigahertz (GHz). One hertz equals one cycle per second, so a value expressed in MHz is, by its very unit, a frequency — the kind of figure used to rate how fast a processor is clocked, not how much data moves or is stored.

Application

The two figures given are classic CPU clock frequencies from early personal computers:

• 4.77 MHz — the clock speed of the Intel 8088 CPU in the original IBM PC (1981).

• 10 MHz — a clock speed used by the Intel 80286 in the IBM PC/AT family (and by turbo-XT 8088 clones).

Because both numbers are quoted in MHz — a unit of frequency — and both name how fast the processor's clock ran, they are specifications of computer clock speed.

Contrast

The other quantities listed are not measured in MHz, which rules them out:

• Data-transfer / bus / I/O throughput is rated in bytes per second (MB/s, GB/s) or transfers per second, not in MHz.

• Storage capacity and storage throughput are rated in bytes (GB, TB) and bytes per second, not in MHz.

Result: 4.77 MHz and 10 MHz are examples of computer clock speed specifications.