I found some other guy having same problem with his Sapphire Vapor-X 4890, I think it is normal for this cards as I read they are maxed @ 86A VDDC
The PC shuts down after a few seconds when I run Furmark. There are no unusual GPU temps according to RivaTuner before that happens (Max temp I saw was 81C but it also happened at 76C). CPU and MB temps are around 48-50 during CPU Stress test, no crushes there. Also I have run numerous benchmarks like 3D Mark 06, 3D Mark Vantage, Crysis, Devil May Cry 4 and played games for hours without a crash or pc shutting down occurring. The problem only occurs with Furmark.
When I repeatedly run the test after each shutdown the PC wouldn’t start when I pushed the power switch and would eventually start after like 30secs have passed. I tried different combos with the cables giving power to the video card, same result always. So I would say it is more likely a PS issue but since I’m an average user I would really welcome some ideas from you guys, thank you in advance.
CPU: AMD Athlon 64 X2 5200+ 2.71GHz
CPU Cooler: Scythe Mugen
RAM: 4GB (2xDDR2 2GB Mushkin 800Mhz Dual Channel)
MB: Asus M3A78 Pro
VGA: Sapphire Vapor-X 4890
PCI-E: Asus Xonar DX
2xHDD, 1xDVD RW
Case: Thermaltake Armor Jr (2x120mm Fans)
Power Supply: Thermaltake ToughPower 550W
+12V1, +12V2 Max Load: 36A
All in stock speeds on Vista 64