Okay, so I'm gonna finally put this problem on a forum...
Which is that in the games Deus Ex: Human Revolution and Metro: 2033 after about 5 minutes with the former and half an hour with the latter, I get a very strange game crash and screen freeze. It's basically the same as any normal freeze, except that over the frozen-screen I get these very strange green (or yellow... im colourblind) pairs of squares, forming columns all across the screen. It's not in high concentration, i.e. you can still easily make out the game, but they are still very noticable. Each pair is about the size of a smiley... (on my screen). I've not been able to find any other examples of this with my searchings, probably due to the difficulty in explaining the problem, not sure if anyone else has. If so please direct me to it. I also couldn't get a screenshot of it for whatever reason. I was running both games near max settings (Deus Ex had also everything turned on/up, Metro was on "Very High") and getting frame-rates way above 30, i.e. smooth.
Specs are as follows (nothing OC'ed):
asus sabertooth p67 mobo
GTX 570 w/accelero cooler
Samsung f3 1 tb hdd
XFX 750w Pro (In fact the problem persisted even after I replaced my corsair tx 750 with the XFX)
Windows 7 -64bit Pro
sounds like heat induced artifacts...
use gpu z to check your gpu temps as well as the vddc temps/volts.
the vddc should always be under 100 more than that and you can expect a lock up/crash/artifacts and so on.
run gpu-z in the background with logging active then look through the log after the next crash.
I have actually done this because I thought that it sounded like heat-related issues myself. I got roughly 50 centigrade on my card. What I do know is that it doesn't measure each VRM and RAM module independently, so I could still get a nice low reading even whilst a component is overheating, which theoretically could still cause a problem. All my RAM sinks are glued on fine, equally I have enzotech heatsinks for the VRMs. The weird thing is though I can play the Witcher for hours and hours and I've yet to have a crash. And I'm pretty sure the witcher is as graphically intensive as either of the other two games...
Okay, I just did a stress test with EVGA OC Scanner, and get 57C at 98% with my fan working at 85% (set to 85% manually). I let the stress test run for 3 minutes and nothing strange happened. Oddly, I got very similar temperatures when my fan was set to about 45%... I can't seem to set my fan any higher than 85% with nvidia system tools, but that's besides the point.
My VDDC was at 0.988v.
Core = 784 MHz
Memory Clock = 2097
I've turned both games down to DX10 now... and I haven't had a crash since with either game. I have the latest nvidia drivers so I can't see how it could be a DX issue. Is it possible that DX11 is just so much harder to run for a GPU that my card overheats in DX 11 but not DX 10?