This is the GPU I have: http://uk.msi.com/product/vga/N560GTX-T ... D5-OC.html
I got it because all the reviews said it was both powerful and quiet. However, whilst I found the first bit to be true, the second not so much!
The first card I had I had to RMA, but it was super quiet even under load. Minimum fan speed on this card is 40%, and that's what it idled at (about 40°C) and it was about 60-70% speed under load. Beautiful.
However, after the RMA the second card was a lot louder. Idle noise levels were fine, but when you started playing any game it would ramp up to maybe 80-90% fan speed (I haven't got actual numbers to hand) and was considerably more off putting.
I put up with it for a while, thinking it may just be because the card was new and it'd settle down. However, this didn't happen. The noise was really too loud, it was harming my gaming experience, even with headphones. So I decided to do something about it.
I tried replacing the factory default thermal paste with Arctic Cooling MX-4. Cleaned it all up nice with white spirit, made sure there was no air in the application, cleared dust out of the heatsink but whoops, I made it worse. It's now 100°C and 100% fan speed. Unbearable.
I've tried redoing it with more and with less paste, but still the same results. Anyone have any ideas what I should try next?