Nvidia GTX980, computer crashes with no BSOD (both DX11 and 9)

[Raist]

Bugcheck 278 - Video TDR Error (the vid card was trying to reset). Barring a driver problem....look to hardware. A very common cause of that can be a power problem.

The reference specs for that line of cards lists as a 165w card...bare minimum recommendation is a 500w PSU. That does not account for overclocking and such, which the OP admitted to doing.

Note also that the reference design has two 75 watt connectors, but the Phantom has one 75w and one 150w. Couple that with the draw from the port itself and there is potential for much more draw than 165 (like, if the card gets overclocked and such--which we know many vendors tend to push things past reference values all the time). In fact...the Gainward sight even states right in the specs that it is boosted (1304 boost over 1204 base on the GPU)...guessing that is why it has a 6-pin and an 8-pin connector (note, that means they want to have access to 225w of auxiliary power, in addition to what can be drawn from the port---we are talking potentially up near 300w in total).

http://www.gainward.com/main/product...3524.pdf?s=414

In testing, the reference cards with only two 6-pin connectors (150w) were shown to hit 175w often under extreme loads. The CPU has also been shown to hit as high as 125 at stock settings under heavy loads, above 160w when heavily overclocked. Factor in any additional drain for the motherboard/RAM if the FSB and such have been tinkered with.... and that 500W PSU may not be fairing so hot. It may not have enough headroom on the 12v supply, or it may have just enough wear on it to not handle the heavy thrashing the game is putting on the system.

Really need to verify the specs on that PSU were sufficient for the requirements of the hardware it is now being asked to support, and if it is questionably close within the breakdown of the rails it should be tested for reliability. Or, at least if the OP has access to a more robust PSU he/she may want to try hooking it up and testing it. Shouldn't need to completely dismantle the system to test it....if the cables are long enough it should be possible to leave the computer's case open and just swap the connections and do a test run.

Edit:
Out of curiosity, I plugged the basic settings in the PSU calculators at coolermaster and corsair. Coolermaster calculated 420w minimum based on reference values (ie: not including the CPU overclock nor the overclocked GPU). Switching the GPU to the 980Ti reference (250w, more in line with the Phantom's power profile) and it switched it to 511W (keep in mind this does not provide a means to compare a CPU overclock). While Corsair doesn't include memory in the options, it does have options for an extreme overclock on the CPU, as well as an overclocked GPU. Regardless if you checked for overclock or not, Corsair spits out for a 600W PSU MINIMUM. Their entry level bronze 500W PSU lists 456w available on the 12v rail...but it is recommending the 600W model instead, which claims 552w on the 12v rail. It is starting to look a lot like a power issue may indeed be in play here.