Unfortunately I believe the coolbits options are a bit broken in the driver. I have two GPU's but can only overclock the first one because the coolbits option is ignored for the second card. I am however able to control the fan speed of both cards using nvclock. But I don't think nvclock has been updated in a long time and I thought I heard something about the fermi cards not being supported. You should still give nvclock a shot though. If you are going to be folding for the long run then maybe you should look into some after market cooling where you can control the fan speed with a physical nob or have the fan setup to just run at full speed. Water cooling would be great too. Now that I'm thinking of this. If you want a cheap way out, you could get a molex to fan adapter, unplug the video card's fan, and plug it into this adapter. It will make the fan run at 100% all the time. One issue you may see from this is the card possibly will report an error on power up, may downclock itself, etc because it nolonger thinks a fan is attached and it may try to protect itself. So you may still want something plugged into the card.
Here is an adapter "similar" to what you may want. You will need to look at the pin setup on the card, also find out if the fan is a pwm fan or not.http://www.newegg.com/Product/Product.a ... -_-Product