FPS sags, where to dig?

Question

Iron

Good day.
There was a problem with the boss's PC. In some games, the fps has become low, because. something with the video card. We see that it is loaded at 99%, but the temperature remains around 55 degrees in its main game, although in other games it also loads at 99% and the temperature already reaches 80, the FPS eventually becomes higher.
Computer config:
Video card - ASUS GeForce GTX 960 Mini OC 2gb
Processor - Intel i5 4430
Motherboard - ASUS H81M-R
Power supply - noname 450v 12gb
operatives Where to dig, what do you think?

Answer 1

In power saving off.

Answer 2

I can also assume that the power supply does not draw, but they are such

Answer 3

Games such that the video should be loaded by 50 percent.

almost all games, even old ones, should load the video by 99% if this does not happen, then this is either a very weak game, or poorly optimized, or a bottleneck percentage. Even for the sake of interest, I launched Hitman BloodMoney, the oldest loads the gtx 1070 by 90-98%.
And what do you drive DotA 1 on it? in anything else, it should not give stable 60FPS + fhd.
this is normal. up to 87 is possible. if you reduce it, then by itself the cooling in the case is done normally, which I think is not in it. But in any case, at 80 degrees, it will not be stupid.
Read my detailed answer here Why does a new computer slow down?