Why does the FPS drop below the plinth after 10 minutes?

Question

Video cards

Help with an endless problem, I go into any game, everything is fine, the fps on any settings is from 60 to 100fps, it takes about 10 minutes and the fsp drops from 10 to 20fps and changing the settings does not help, according to MSI monitoring, the voltage on the video card jumps 30-45-50w , although during the course of the game 80-100w and the load on the video card (gpu) jumps 0-100%, the processor is rarely loaded at 100%, usually around 80-90%, the temperature is normal everywhere. Asrock 960gm-vgs3 motherboard, fx6300 processor, sapphire radeon rx 470 Nitro 4gb video card, 12gb ram, barakuda 1tb hard drive, zalman zm400-le power supply, Windows 10 from Microsoft is not pirated. Could it be a lack of nutrition? Or something different? Any answer will be glad, thanks.

Answer 1

The feeling that the PSU is overheating under load.
And then - the drop in output power.
You need to test the PSU or try a parallel power circuit (plug the connector from another cable for the second power supply of the video card).

Answer 2

I threw a second power supply on the video card, it became much better, but periodically such a picture still pops up.