My current best setup is 925/1250 at 0.962V for 560 kH/s at 170W or 3.29 kH/s/W, after many hours of systematically mapping gpu clock (
3.3 kh/J is great man!! Have you done any work with 58xx cards?
Cheers!
Just the 7950 but if I do I'll share it here. I think I mostly got lucky just lowering the voltage at the stock gpu clock and memclock. I looked all over for more efficient combinations and nothing was as efficient as 925/1250/0.962V.
I have four Sapphire 7950s and can confirm that these are by far the best settings Ive found so far, thank you for sharing them.
I run four cards at 925/1250/0.950, although that 0.950 is set via --vddc in cgminer, and GPU-Z shows ~0.996V for all GPUs. So I guess they are actually not undervolted at all.
I could probably squeeze some more efficiency out of the system by setting each card to its minimum stable voltage, but mapping the correct cards between cgminer, GPU-Z and Trixx/Afterburner is too much of a hassle.