fan speed controller for nVidia graphics card?

[Icepick]

Can anyone recommend a software fan speed controller that I can use to modify the speed of the fan on a nVidia 6800GT?

I'm using an NVSilencer with it now and the fan makes an irritating buzzing sound. I'd like to lower the fan speed and, hopefully, reduce the noise coming from the graphics card.

Thanks!

 

[xtknight]

RivaTuner.