I'm new to mining and I'm wondering what the best settings for a 5830 are.

I'm currently testing one 5830 @ clocks 975/300 with phoenix miner with phatk kernel with 3% mod

with the following arguments VECTORS BFI_INT AGGRESSION=7

Running windows 7 x64, 11.6 drivers, 2.1 sdk, i can only get an average of 270/280 Mhash/sec.

What are the best settings and options that will maximize my performance ?