Learn in the textbookTypes and Performance of Processors
DefinitionClock frequency (クロック周波数) is the number of cycles (ticks) per second of the clock signal a processor uses to keep its operations in step, measured in Hz (hertz).
ExplanationThe length of one clock cycle is the reciprocal of the frequency, and the time one instruction takes is the number of clocks it needs × the length of one clock cycle. For example, an instruction that needs 8 clocks at 4 GHz takes 2 nanoseconds each, so it can run 500 million times per second. Performance depends not only on clock frequency but also on other factors such as the number of cores and cache memory.
AnalogyIt is like the call that keeps rowers in rhythm in a boat race. The shorter the gap between calls, the more strokes fit into the same time.
Memory hookA clock tells time, and the clock signal ticks at fixed intervals like a second hand. The G (giga) in GHz means 1 billion.