What causes the hertz values ​​to jump?

Question

Computers

The mouse in the drivers has a polling frequency of 500 Hz, I check the hertz through the software. With fast mouse movements, it shows an average of about 200-300 Hz, but there are also values ​​\u200b\u200bup to 100 Hz and more than 1000 Hz. In general, chaos is complete. i5 based computer. Why is this happening, how to find the culprit? It's not about the mouse, but, apparently, in the system (win10) or in the hardware, but the temperatures are all right. Performance in games dipped, FPS sags a lot. I think the problem with mouse hertz is a side effect of the problem itself. How to find out what is the reason for this? Same behavior in safe mode. There is no extra load on the CPU, all components pass stress tests perfectly.