I have finished building the -30C Chiller for my 7950GX2s and X1900XTs.
Just tested overclocking the 7950GX2:
Tests done on Intel XBX Motherboard with X6800 Conroe. With -30C Ethanol running through the waterblocks, 3C reported on GPU by Rivatuner:
So what kind of performance did I get? I pushed the GX2 to around 766MHz Core and 912MHz Memory. With Conroe @ 4.5GHz Tests, a bit more than 13,000 3D Mark 06 was acheived.