Windows 10 – CPU Utilization in Task Manager

Many apps don't use all cores. They aren't programmed for it. Then they will use one core and will overload it.

But you can tell Windows to run that process on 2,3, ... and in all cores.

For doing it, follow these steps:

1. Open Task Manager
2. Select tab Processes
3. Right click and select 'Set Affinity'
4. Select on which cores you want to run process.

Most processes spend their time waiting (waiting for a network packet, waiting for the user, waiting for some other process/thread, ...). It does not make sense for the operating system to schedule that process at all - it would just return immediately and continue to wait. Uselessly looping draws power.

Instead, if all processes are waiting (more precisely: if they are blocked), the operating system will turn the CPU off, putting it into a sleep state. The "thread" which does this is called the idle task. The CPU will then stop processing instructions until an interrupt fires (telling the OS that something happened).

While the CPU is not running, the clock continues to run however. So if you turn the CPU off every 100ms, and the CPU wakes up 50ms after you put it to sleep, your CPU is 50% loaded. The same idea applies to multi-core CPUs.