What is the highest clock rate that has been achieved? I find anything above 900MHz causes the hash rate to drop in half even when my temperatures are below 80C. I may be power limited or can I play with the voltages somehow?
You need to up the voltage. I've hashed as high as 735-740 GH/s at 962Mhz, with high hw errors and bouncing off the 104 mark.
I'm getting a pretty solid 700-710gh/s at 925-950.