When you minimize the game and while the game is minimizing is when it spikes like that. While the game's running, it holds from about 60%-80%. You've got a dual core processor. You should be able to run it. I suggest that if you are worried look at what is chewing up your processor besides CF.
Also, Try this program. Game Booster: http://www.iobit.com/gamebooster.html. Its free, ive used it before and it is great for squeezing excess power out of your system (especially bypassing some of the crap windows does).
My processor is a Six Core AMD Phenom II X6 1100T Black Edition. So i desperately need more processing power 
