It may be best to stress test the GPU to see if it's the culprit.
Run Furmark to stress test your GPU. Video Card - Stress Test with Furmark
NoteRun Furmark for around 30 minutes.
WarningYour GPU temperatures will rise quickly while Furmark is running. Keep a keen eye on them.
It passed the test. Max. temp was 73 Celsius.
Could a bad DVI port be a problem in this case? My GPU has DVI-I and DVI-D port, both dual link. I used DVI-D port until now because I use DVI cable (single link) without any VGA converters so I used DVI-D instead DVI-I. In the GPU manual the DVI-I is named Primary DVI port and DVI-D is secondary. Now I haven't had BSOD or freeze for 4 days (since I started using DVI-I port with the same DVI cable as before). It is too early to say that the problem is solved because couple of times it passed 7-10 days without BSOD but I'm curious about this.
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