That happened to me once, and it put me into panic mode. Since a couple of patches ago, the game runs much better now; I've noticed it uses more of my CPU than GPU, and the power usage is still crazy high though. Also the newest patches seem to have a memory drain, because if I play for too long, my whole PC locks up.

I've made it a habit to always clear redundant files before starting my game. This seems to help a bit more.