My miners went from 355 to 362 on 6950 based systems running ubuntu natty 64 bit.  I tried various flags, and this is what worked best for me:

-k phatk AGGRESSION=12 BFI_INT FASTLOOP=false VECTORS VECTORS2 WORKSIZE=128

WORKSIZE=256 was slightly slower. I tried VECTORS4 just for fun, and it dropped down to 300 or so.

My 6950s are running at 880Mhz w/ 800 mhz memory clock.  (no shader unlock)




Thank you for all of your hard work.  Donation sent.