I've got a bit of an issue with Desktop #2 (in my sig) - I built it to be a quiet machine, and accordingly bought some 1200rpm slipstream fans for the case.
Problem is, it's still making a right old racket, and I'm pretty confident that it's the CPU fan - stock AM2+ heatsink. The motherboard's automatic function doesn't seem to work very well - it's spinning far more quickly than it needs to as far as I can gather, because even when I've dropped the RPM manually with Speedfan and got Prime95 going the CPU still refuses to get hot. Google seems to confirm that the motherboard isn't great at getting the speed right.
So I've got myself some molex adapters for the case fans, so they aren't plugged into the motherboard any more, but I'm not sure what to do with the stock fan. If I put the molex adapter on them I'm guessing it'll spin right up to some crazy speed... what do you reckon is the best thing to do?
I'm not averse to buying a replacement heatsink, if it's easy to fit, but obviously if I can make the old one work then that would be better. And even if I do buy a third-party heatsink, I'll need to be careful - if it runs off PWM/voltage from the motherboard it'll be running at very high speed all the time.