Spintires man ? Really ?
If it was witcher 3, then by all means. It would be worth the trouble.
Try your gpu in another mobo first.
Seek professional advice and testing with appropriate tools. An honest pro that is.
I could be the worst noob in the whole world for all you know.
Only when you have trully isolated the problem should you act.
Thanks for time, effort and feedback on this forum.
gigabyte X58A-UD3R rev.2, core i7 975 3.9ghz (stock voltage), windows 8.1 64-bit, corsair 12gb DDR3 1600mhz 7-7-7-20 RAM, xfx HD 5970 + gigabyte HD 5970 (950mhz/ 1100mhz), coolermaster ultimate 900w PSU.
AMD Catalyst 15.4 beta