I'm having the exact same problem. I have tried several things to no avail. :( I read a similar issue regarding CPU throttling here: http://www.google.co...ltPhBfj0Lvovz7g With the lag gradually increasing in the first 3 - 7 minutes it would appear to be overheating related.. but alas.. Looking at Throttle stop it appears that the CPU isn't being throttled. I'm leaning towards it being a RAM issue, with the FPS dramatically increasing when I tab out and in, or relaunching the game.