Well yeah my PC is old but I can run some older games perfectly fine. I played League of Legends on low graphics at 60fps but then after a few hours or so the fps started dropping from 60 to like 10 for a few seconds then it returned back. Similar thing happened with Risen, a few months ago when I played it, it ran fine, but now it starts to have same fps drops like league of legends, it runs fine then it slows down for a few seconds then it comes back. Any way I can fix this?