Your hardware is fine and the game doesn't support more than two cores anyway. Set general drawing quality to 8(which looks exactly the same as 10... really) and the game will run with ~60 fps. Btw you can't measure your GPU-usage correctly. Don't believe what that **** piece of programm tells you xD. SE will most likely work on the performance once the gameplay is fixed. If you have lots of visual lags in the game then your hard drive might be too slow.