Why did the i7-9700F CPU frequency drop?

Question

Processors

Gaming PC, used as usual, the last week it began to make noise with coolers. Today I started to hang hard at everyday work, in the Manager, the CPU frequency dipped from the average for my PC 4.3-4.6 GHz to 1 GHz. How to fix it?

Answer 1

Coolers are noisy => not cooling well => overheating
Run a load test (OCCT for example) and look at the temperature. If the temperature is out of range, change the cooling.

Answer 2

The frequency depends on the load. If there is no load on the processor, then the frequency drops.
For the i7-9700F, the base clock speed is 3GHz, and anything more is already using Turbo Boost. And more than 3GHz should only be under serious load.