Computer shuts down after about an hour of gaming

[Hyperion_Toaster]

I've been having trouble for a while now with my computer randomly shutting down after about an hour or so of gaming. It just shuts down with no warning and then it boots back up a couple minutes later.

It only seems to happen on certain games though, which is weird. I can play Skyrim with custom HD texture packs and Borderlands 2 at ultra settings for hours on end with no issues, but Farcry 3 or Bioshock Infinite shut down after ~60-90 minutes.

I thought it was overheating at first, since the top of the case is mildly warm to the touch after it powers down, but I've tried numerous different types of temperature monitoring software, and nothing seems to be overheating; my CPU runs at about 50-60 degrees in game, and my GPu up to ~80. It could be the motherboard overheating, but it's difficult to get a decent reading on that (seems to be around 40+ degrees when it restarts). These may or may not be entirely accurate, as I've had difficulty finding software that makes decent temperature logs.

My system specs:
CPU: Intel(R) Core™ i7-3770K 3.50 GHz 8MB
PSU: 850 Watts - Corsair CMPSU-850TXV2
GPU: AMD Radeon HD 7950 3GB
RAM: 16GB (4GBx4) DDR3/1600MHz Dual Channel Memory

Any help would be greatly appreciated, thanks.

 

[Onus]

Those components are good. What is the motherboard? If MSI, I'd suspect overheating VRMs.
Are the fans in your case arranged for maximum airflow, or are they fighting each other? Front, side (if present) and bottom (if present) should be intake, and rear and top (if present) should be exhaust. Unless it draws its own air from below the case, remember that your PSU is also an exhaust.

 

[JackNaylorPE]

Have you run memtest86+....With 4 modules I have sometime found a need to reduce CAS timings below "advertised" settings, especially on MoBo's or with PSU's with less then stellar voltage regulation.

 

[Hyperion_Toaster]

Those components are good. What is the motherboard? If MSI, I'd suspect overheating VRMs.
Are the fans in your case arranged for maximum airflow, or are they fighting each other? Front, side (if present) and bottom (if present) should be intake, and rear and top (if present) should be exhaust. Unless it draws its own air from below the case, remember that your PSU is also an exhaust.

The motherboard is a GIGABYTE GA-Z77-D3H if that helps.

I'm not sure about how optimal the airflow is the rear is definitely exhaust and the front seems to be the same (difficult to tell though, either way it's not terribly strong). There's also a side fan but it isn't running, haven't been able to quite figure that one out. It might also be worth noting that the case is somewhat open (as in grate-like) on the top. And ah, I didn't realize the PSU had an intake on the bottom; the computer has been sitting on the carpet for a while, so I'll find a way to prop the back end up for better circulation.

Have you run memtest86+....With 4 modules I have sometime found a need to reduce CAS timings below "advertised" settings, especially on MoBo's or with PSU's with less then stellar voltage regulation.

I haven't run memtest86+ yet, though I've been meaning to. Ran the Windows 7 memory test last night though and it didn't bring up any issues, should probably still try memtest though.

 

[Onus]

If your PSU has been getting no airflow, then it might be what is overheating and shutting off. I have my cases resting on plywood pieces so the carpet doesn't block PSU airflow.

 

[Hyperion_Toaster]

If your PSU has been getting no airflow, then it might be what is overheating and shutting off. I have my cases resting on plywood pieces so the carpet doesn't block PSU airflow.

Huh, well what do you know, propping up the back end of the computer seems to have worked. I didn't even consider that the PSU might be overheating. Thanks!

 

[Onus]

Great! That's a good PSU too, so it probably did not suffer any long term ill effects.