Sometimes, when I start games, my FPS is extremely low (sub 20fps) for no apparent reason. I have a very powerful GPU and CPU (1080 and 6700k, respectively). Normally, I get very high FPS in these games and it appears to happen at random. This does not stop until I restart my PC. I have no idea what could be causing this or where to start. As far as I know, my drivers are up to date. This only happens on some games. Some run fine, while others have this problem. What can I do to fix this?