I have this problem as well: an incredibly high CPU usage that basically drains all life and movement from my proccessing. The really crappy part about it is that my brother and his girlfriend are able to play it on their own seperate PC's. My brother's is practically state-of-the-art beast, but his GF's is the exact same PC build as mine, but with an older and a little less efficient graphics card, so it shouldn't be the system's fault: it must be the game. I've tried nearly everything to try and boost performance except wasting more money, but I still come up with nothing.