Why does FPS drop in games after minutes of inactivity?

Question

Windows

In any game, after 1-2 minutes of inactivity, terrible drawdowns of FPS to 5-10 begin. This happens during any cut-scene or just when waiting for about a minute. If after that you press something, after half a minute everything returns to normal. What can be wrong?

The feeling that due to inactivity, the PC begins to save resources. Power settings - maximum performance. There are no drawdowns during the game itself, the PC is quite powerful.

Answer 1

Apparently, power saving is turned on, some kind of EPU or its equivalent. It is necessary to disable it in the BIOS, if it confuses.