Last night I made two tried: 1st is not OC and keep the ram in max, it didn't reboot, 2nd is lower the ram (fron 2T to 3T) + OC, it didn't reboot. Before I made this two tried, I also turn on two fans inside the case, because of too noisy, I turn it off(total 3 fans). Now I'll go back to OC + max the ram, turn on 3 fans and see what happen.
The games that it reboot: black and white; Star wars Jedi knight II.