I have an i7-4700MQ in my laptop, along with a GTX 765M, and while my GPU is typically working hard, the CPU never goes above 25%, and is usually lingering around 22%. I've tried tinkering with all the graphical options in the game to see what does what to my rig, but it seems to stay at 22% no matter what my settings are.

I Also tried -exThreads=7, which made the game use 7 threads instead of only 4 (Don't know why it didn't use more threads from the beginning).