true except what happended to me: my G4 dual (aircooled) was terribly loud and the only radiator i ever needed im my room. When cleaning it i found that it was sucking most cooling air at the bottom and that the grid there was covered with a layer of dust. Additionally to cleaning that i changed 2 40gig harddrives for one 250gig. Now CPU temperature is down from 60° to 45-50°, its waay more silent and i need my radidator sometimes.