CompTIA A+ Certification All-in-One Exam Guide

All modern CPUs run at some multiple of the system clock speed. The
system bus on my Ryzen 7 machine, for example, runs at 100 MHz. The
clock multiplier goes up to ×32 at full load to support the 3.2 GHz maximum
speed. Originally, CPUs ran at the speed of the bus, but engineers early on
realized the CPU was the only thing doing any work much of the time. If the
engineers could speed up just the internal operations of the CPU and not
anything else, they could speed up the whole computing process. Figure 3-22
shows a nifty program called CPU-Z displaying my CPU details. Note that all
I’m doing is typing at the moment, so the CPU has dropped the clock
multiplier down to ×15.5 and the CPU core speed is only 1546 MHz.
Figure 3-22 CPU-Z showing the clock speed, multiplier, and bus speed of a
Ryzen 7 processor hardly breaking a sweat