So i just got the gtx 780 the other day and when i set it up at first it ran fine. I was testing it out on assassins creed 4 and everything was working. But when i was playing it today after about 2 hours my computer shut down while playing it. I figured something had just gotten to hot so i let it sit for an hour or so and when i went back and started the computer back up the fans were going crazy and i wasnt getting a picture. I pluged my monitor back into the motherboard instead of the grapincs card and it turned on fine. Thats how iv come to the assumption that thats the problem. I didnt do any overcloaking by tge way im just running on its factory settings like everything else. Also it might be worth mentioning that after it shut down it restarted and everything was working fine and i checked the tempeture of the graphics card and it was back to normal and so i tried to start the game up again and thats when it crashed the second time and thats when i started having these problems