Hey guys,
I've done a fair bit of CPU overclocking, but I've never touched GPU overclocking. Until about 2 hours ago.
First of all, my specs:
GA-990FXA-UD7
FX-8150 @ 4.2GHz (yes it's stable)
2x8GB 1600MHz CL10 RAM
2x GTX660 (1 MSI TwinFrozr with a slight factory OC, 1 MSI non OC'ed with a single fan cooler)
Corsair GS800
I can't get past +50MHz, regardless of what voltage I set. I use MSI Afterburner and Heaven for testing. Right now I'm at +50MHz, +160MHz memory @ +12mv and powerlimit is set to max (119%). Anything higher, regardless of voltage results in a black screen for a few seconds before resuming as normal in random points during testing. Temps are completely fine, 73 degrees Celsius max, less on the TwinFrozr card.
Is this because my cards aren't completely identical? Is there something else I'm doing wrong?
EDIT: Posted early accidentally, pressed enter with my elbow -.-
EDIT2: More weirdness, max clock speeds aren't consistent between Afterburner and GPU-Z. The slowest card is pictured in GPU-Z.
http://nl.tinypic.com/r/2hntheq/8