6800gs topping out at 520/675 w/silencer??

[grenadier]

I just got an evga 6800gs and the highest I can get it without artifacting is 520/675 which seems a little low - especially since I've got an nv silencer on there with AS5.

I can run 3dmark05/06 artifact free at higher speeds, but games inevitably start sh*tting bricks at those clocks. My load temps using rthdribl dropped from 86C to 74C with the nv silencer (and should continue to drop while the as5 is curing), but the lower temps aren't allowing me to push the core any higher. Any suggestions for squeezing more performance out of this card?

[Levish]

The silencer isn't the best if you want low gpu temps, it's a very good solution if you want quiet cooling.

[gocchin]

Increase the voltage... you are probably voltage limited at this point.

[grenadier]

Increase the voltage...

Could I do this by editing the bios? Is there a guide floating around?

/edit i checked with rivatuner and apparently the fan was only ramping up to 50% speed max so i put it up to 100%. it's definitely louder, but i'm not getting any decrease in temps. strange...