Not sure why you're saying the KH you're getting is at "stock" clocks.
He said stock volts

Ah OK. But he did say he's getting ~720 on stock clocks from a 280X which I find equally outlandish?
The Powercolor 280X has a stock core clock of 1030Mhz. Factory-overclocked, I guess. Which is why I could only overclock them from 715Kh/s to 740.
Thanks to you I'm now getting ~615KH on my 7950 using Karloth and these settings:
--xintensity 4 --worksize 256 --shaders 1792 -g 2 --gpu-engine 1055 --gpu-memclock 1250 --gpu-powertune 20 --lookup-gap 2
Didn't have much luck with the fan settings and the temps are still below 80c (without any evident throttling) so I'm cool there. Still beats the 550KH I thought was the maximum for this particular card. So unless you have any more advise I thank you muchly!
