You should enable sync. v sync will match your frames to your monitor's refresh rate. If your monitor is 60 mhz, you can't get any better than 60 fps, Even if your being told the game is rendering at 100 frames, you're just wasting electricity and heating up your room. I have a 144hz monitor and I run 36 fps. If I let it run at 72 fps (half of my 144hz) my temps on my card would be in the 80's. At 36 I get temps in the 50's and notice no difference in gameplay and don't sweat nearly as much.