g-ram: I use all stock fans with my computer (it was a monster on a budget xD ), and, if the room it was in was completely silent, you would be able to tell when its on or off. Definitely. But the room I am in has all the other computers in it and a really old, and loud network switch. So, by comparison its quite quiet. But, it does cool quite well... if I hadn't taken out the fans on the top to fit in the PSU, it would be even better (better flow, sucking in and blowing out in two directions).