what physically determines the speed of a processor?

Question

what physically determines the speed of a processor?

In: Technology

Answer 1

There are 2 components that determine CPU speed: the front side bus (FSB) which is a clock on the motherboard itself typically running at 100 MHz, and a “multiplier” which is on the CPU and sets how many CPU cycles to run per FSB tick. So for a 4 GHz CPU the multiplier would be 40.

Changing the CPU speed requires changing one of these two values. The multiplier is the easiest and generally safest to change, but only works in increments of 100 MHz and some CPUs are multiplier-locked preventing this.