Do you know of a more stable or better performing minter for windows users that do keccac?
There is no other minter for GPU afaik.
The settings I use to get 215 MH on a HD 7970 are:
gpuIntensity=512 (If I set it to 750 I get 220 MH, but GPU usage goes from 97% to 98%, and that's the difference between being able to watch flash videos in a browser without crashing, and with my display driver crashing)
gpuDevice=0,256
I overclock my card heavily. That's a whole other subject you had better google yourself. If you have a high quality card and good airflow in your machine you can increase your hashing power by about 25%, but expect lots of noise, heat (= more electricity), and of course lots of crashes and tinkering before you get it right. But that's the sport =)