I have an HIS HD 7870 IceQ 2GB GPU
I am trying to overclock using MSI Afterburner. I've researched a lot into overclocking. I've taken baby steps trying to find a stable overclock. But so far I have ran into nothing but problems.
Checked for artifacts using GPU Tool. Found none. Decided to try a game while monitoring temps. Got into game, went to alt tab and got the Windows 8 blue screen "Oops, PC ran into a problem". Temps were at 48 when my PC crashed, and GPU usage around 35%.
At this point I only had my core clock increased about 100mhz over default. I have a 600w PSU (CX 600). 80plus bronze.
A couple friends told me 600w is more than enough for this GPU and the rest of my hardware.
Have you gone into Afterburner settings and unlocked the voltage options so you can increase it in concurance with clock. 7870 is like an OCed 7850 so the clock has already been pushed some so you will need to push voltage to increase more
I ended up at 1263 voltage, power limit +20, 1170 core clock, 1320 memory clock. Temps never go above 60, played for about 20 minutes.. no crashes. Not sure if there will be problems later on when I play for several hours, but we'll see. For now, it seems good.