How on earth did you get them 7970s running stable Mike ? I can do stock ,but once I OC them I get freezes everywhere...

Show me your magic

Have you tried disabling ULPS? I use Team AU's ULPS tool, it works great. Have had no issues since and the reference card can only run those clocks, other card runs faster.

http://hwbot.org/forum/showthread.php?p=216077

I use Trixx and disable there ULPS;) Also worked like a charm:)

Dunno I'm on the GA 790X-UD3 board and I fear it has some issues with 7970 cards in crossfire... single card it all clocks up nicely. In crossfire it was lockup galore, loosing display,... rig was very unstable...

We used Trixx and even registry setting to disable ULPS... reinstalled OS, tried other drivers flashed 3 biosses for the board... no go...

Pretty clueless besides to point the finger at the Giga board...