I am having the same problems, I have tried every fix in the book and have gotten next to zero increase in fps. I get 45-60 in singleplayer but when I join a server it all goes to hell and I get about 10-15fps. What makes it even worse is I just went and bought a gtx 760 for $300 thinking my old graphics card was the problem but that didnt help at all. I have a i7 920 3.7ghz also so my system should be able to handle this game no problem. I'm in the same boat as you buddy.