some as you might know you can flash to the 6970 BIOS which ive tried but it was using too much power but here's the link if you want to see it
http://www.techpowerup.com/articles/overclocking/vidcard/159and a video on how to do it
https://www.youtube.com/watch?v=zvp5-SlV1Q0i did do it but i had a few problems like the blue screen of death so i had to swich the VBIOS to 2 then had to flash it back to normal in one then i found a 6950modded much safer i think it might be the same but this is what my results are.
6950modded with OC 6950modded without OC
and my core clock is 890 and my mem 900(what is the use of memory clock?)
my Card is a refrence design ATI Radeon HD 2x 6950