I do have the same kind of problem, I think it's related to the game/engine. cause even lowering the resolution does'nt help (i play with graphics on low), and it's not internet code related either (have this on solo).
Use console then type : peroverlay.drawgraph 1
it will show the CPU/GPU usage and my CPU spike sometimes to the top of the screen, which is obviously a bit weird.
I also get sound loops constantly and of course these CPU spikes makes my fps drop very low.
my card hd5870
cpu e8500 @4.3 ghz
4gb of ram
windows 8 64 (had 7 64 before)
BUMP
bump
