I have problem with my GPU HD 6950 XFX dual fan with 2GB VRAM. When I play games, it often crush (Example: Watch dogs on with High texture and Ultra graphic), also other games (As COD MW3 MP on ULTRA). I have 22" monitor with 1650x1050 resolution and when i start game, everything is good and I can play sometimes 5 minutes, sometimes 1 hour. If I downgrade GPU to 500MHz and -20% power i can play normal, but i don't want to play with slower settings.
My configuration is:
CPU: Pentium G4560
RAM: 4GB DDR4 2133MHz
PSU: FSP group 450W 80plus
MBO: ASUS B150-K
SSD: 120GB Radeon
Also GPU temperatures under load is 52-55 C.
What 3rd party software are you using to control your AMD GPU card power & fans? Also what are the temps of your GPU under heavy load?
Have you tried using Wattman or OverDrive to control your GPU card Power and Fan on your AMD GPU Card? Are you Overclocking your GPU when it crashes under heavy load?