What drivers do you use?

[-ck]

I expect that intensity 7-9 is optimal for just about every available card. Increasing intensity beyond this will likely make the displayed hashrate fluctuate more wildlly, but the average hashrate will be the same, and utility is unlikely to be affected positively or negatively. However, depending on which SDK/driver combination you use, CPU usage may rise quite dramatically when you get beyond the optimal value.

[humanage]

OP here. After messing up my AMD drivers, The closest I can get to my 655MH/s is  620M/s.
I'm using drivers 11.10 and SDK 2.4, with clocks at 1020core and 370 memory.
I've tried playing around with clocks, but barely a difference, same with GUIMiner Pheonix flags(-k phatk VECTORS BFI_INT FASTLOOP=false AGGRESSION=10)
Should I just re-install my windows 7(even tried service pack 1)?
 

[ChanceCoats123]

Running 11.12+2.5 over here with my 5870 @ 950/300. In cgminer 2.2.1, I get ~ 385mhash/sec and in poclbm I get ~405mhash/sec at the same settings.

Now I'm just not sure if poclbm will actually submit valid shares for me. I mine with P2Pool so I was using cgminer since it is the recommended miner. However I can't argue with 20 extra mhash/sec. Both of my shares so far were rejected though. I'm not quite sure what's up.