I'm having the exact same issue. I'm running an i7 3840. It worked yesterday for a few hours with no issues. Today, I've been trying to play for about 80 minutes but it's crashed 3 times. Once while loading and twice in the middle of playing. There's no frame rate drop or any signs of the system struggling or anything and it just crashes. The screen go red for about 10 seconds then the computer restarts.