Unclear cause of CPU Throttling?

Question

Processors

After a long time, I suddenly wanted to play on my home desktop and suddenly encountered brakes that didn’t exist before. Began to understand.
At first I sinned on the video card, but everything seems to be in order with it - and the temperature is moderate and the frequencies do not jump.
Then I cleaned all the iron from dust, there was a lot. I washed the processor heatsink even under water, smeared fresh thermal paste. All this did not give a noticeable effect, I continue in a different way.
I start the game, and on the second monitor - all sorts of utilities.

I noticed that when the temperature reaches 54 degrees (Core Temp), the processor slows down (TMonitor) the frequency (?) until the temperature drops a little. Judging by cpu-z, neither the multiplier nor the frequency jumps, although I don’t even know if this should be displayed there.
In the BIOS, I sort of turned off SpeedStep and others, set "maximum performance" in the power consumption settings (but it seems to me that this should not affect).
Processor i5 750, mother Asus P7H55D-M EVO

Answer 1

There may be a problem with the power settings.
Go to: Control Panel\All Control Panel Items\Power Options\Change Scheme
Settings Click "Change Advanced Power Settings"->"Processor Power Management"->"System Cooling Policy" Set the value to "Active".

Answer 2

First, update your motherboard BIOS to the latest version.

Answer 3

Try blowing the power subsystem near the processor. In the absence of overheating of the processor itself, throttling can be caused by the power supply.

Answer 4

It seems that he solved the phantom friezes by pulling out the Creative X-Fi PCI-E sound card, it does not have its own DSP and therefore the sound is processed by the CPU. Seems to ease