I think something is wrong with whatever senses/controls the fan speed on my EVGA GTX 570.   My temps are super-cool (at 32c idle) and everything is telling me my fan speed is at 40%.  However it sounds like a hairdryer almost and I know it is running close to 100% because if I stop the fan manually the noise stops completely.
 
Adjusting the fan speed using EVGA precision has zero effect on the noise, from 40% all the way to 100%, so I don't think it's working correctly.   However when I do adjust this, I can see the fan speed sensor claim to reflect my changes (in both EVGA precision and gpu-z).
 
 
Something is wrong.   Anyone else seen this?