Private solution to performance problems. (Dying Light)

Hardware: video - GTX 970, processor - FX 8350.
It's no secret that with this hardware configuration there are constant fps drops in the game, approx. from 60-100 to 15-25.
I managed to get rid of this problem at the moment by removing the cover from the case. To all appearances, the cooler cannot cope with maintaining the temperature of the processor and therefore it starts to produce less performance. Also, for me personally, after 30-60 minutes of playing, sometimes the computer freezes and only a reboot helped.
I think that in order to avoid removing the cover, it will be enough to simply increase the rotation speed of the fan by hand.