Microprocessor performance monitoring

The processing unit is one of the fastest components of the system.

It is comparatively rare for a single program to keep the microprocessor 100 percent busy (that is, 0 percent idle and 0 percent wait) for more than a few seconds at a time. Even in heavily loaded multiuser systems, there are occasional 10 milliseconds (ms) periods that end with all threads in a wait state. If a monitor shows the microprocessor 100 percent busy for an extended period, there is a good chance that some program is in an infinite loop. Even if the program is "merely" expensive, rather than broken, it needs to be identified and dealt with.