Computer stops displaying to monitors at random.

[Ignorance101]

Okay so yesterday I encountered a very strange issue while i was using my computer. I was playing Skyrim just fine, then all of a sudden both of my monitors went black and said that they were not receiving any signal.

This happened without warning and windows didn't make a sound. In fact, shortly after the monitors went blank, all sounds from my game(the only program producing sound at that time) ceased. The strange thing is that the computer shuts down normally upon pressing the power button, so it would seem the problem may be with the graphics card, but I have no way to be sure.

I wasn't exaggerating when I said that this occurs at random. It occurs when I'm playing any game, and at random points. It can also occur almost immediately upon booting into the desktop, before I've even launched anything. I have up-to-date drivers for my card, and nothing is user overclocked, although the GPU was factory overclocked by EVGA.
Another thing that might be noteworthy: When I press the power button after having to shut down, the computer Posts once, then does it again before booting the OS, which I've never seen before.

Any help is much appreciated

Specs:

Windows 8.1 Enterprise
Intel I5 4690K @ 3.5Ghz w/ Stock cooler
EVGA Geforce 960 @ ~1.2Ghz w/ Stock cooler
16GB DDR3 RAM, multiple vendors, 4 sticks of 4GB
Not exactly sure what my motherboard model is, but I can find out if it's necessary.

Edit: Sound DOES keep playing after the screens stop displaying, at least youtube videos do. Also, to revise my final note: The computer posts then tries to load the OS for a split second THEN it repeats the cycle before finally booting fully. Small detail, but it might be useful.

 

[Tradesman1]

What PSU? Also might want to try raising the DRAM voltage + 0.05, with mixed DRAM it may not be as stable as it should be.

 

[Ignorance101]

What PSU? Also might want to try raising the DRAM voltage + 0.05, with mixed DRAM it may not be as stable as it should be.

It's a Corsair HX850 Platinum PSU, fully modular. The 960 GPU requires a single 8pin power connector.

My computer completely failed to boot earlier with the 960 in. It wouldn't even Post, it just kept restarting the post cycle, and all the while, nothing was showing up on screen. I replaced the 960 with an EVGA 640 that I had sitting on a shelf, and it has no issues at all. At this point I'd guess that the 960 is dead but I still have no idea why. The only strange thing that it was doing was always running at its maximum clock speed, but my CPU does that as well. I've never heard of that causing an issue, but I may just be misinformed.

 

[Tradesman1]

Might try the 960 in another rig