I have a Alienware X51-R2 pc and my GPU is a NVIDIA GTX-670. Whenever I play ressource intensive games like Assassin's Creed 4, the computer would crash (black screen) and the fan would go as loud as a jet. I've determined that the issue is with the GPU and that it's probably overheating.
I've tried to play the games and monitor the temps at the same time with speccy, the motherboard and CPU sometimes go to as high as 70°C. the GPU is averaged between 50°C and 60°C (it might go slightly higher). And those are the results when I use a program like MSI Afterburner to speed up the fan. Even with that program the GPU ends up overheating.
I use the latest drivers, I've also tried with older drivers. I'm not sure if those problems appeared after an update but up until now I've had no trouble playing high-end games and I've had that PC since July 2013.
The PC has been opened and cleaned, the place where it is resting lets the air flow and I have not modified any of the parts inside, these are still the originals and untempered with.
70c is not too hot for a video card GPU (or CPU).
If it was heat related, it would throttle back or maybe the gpu driver would crash, but it would be controlled and would write an error.
Just turning off is usually hardware related. My guess is PowerSupply or just general lack of power at max/peak usage.
Power supply? Really? Yikes...
Even though the fan was still on (like crazy)? Sometimes it spins for like 5-10 mins until it cools down and sometimes it just reboots.
But let's say it is a power supply problem what should I do?
Use graphics card tuning software like MSI Afterburner or EVGA Precision to limit the power usage of the card - this can be done by setting upper limits on the max clock frequency/voltage of the card. You can read up online on how to do this.
I used MSI Afterburner and set the limit to 120% and gave my fan a profile to keep it cool. It sure allowed me to play and I was under the impression that the problem was solved but it happened again. This doesn't make sense I was able to play all that without using such software before.
I've had 3 long sessions of Ac4 with that solution. I feel like we're starting to tap into the solution but not quite there yet.