Posted 09 March 2009 - 12:20 AM
Sounds like a definite fan issue. Most fans run on ball-berrings (bbs) that are usually greased up to allow the motion of the fan to spin. Once these berrings lose that oil/grease, they begin to make the fan shake. This causes a noise that sounds like someone might be holding a pin to the fan blades. Once this happens, the fan spins at a slower speed. I personally have seen CPU fans go from 2100 RPM, to 1200 RPM just because of this. This will make your processor run hotter than normal. One example is the VISIONTEK HD 4870, which spins at 25% by default. Mine was running 81 degrees C, but I manually changed it to stay at 45% and now it runs at 42 degrees C. This is a huge difference for just 20%, and you could possibly be loosing 30-50% due to this. I would replace the problem fan and check it.