Hi All I've heard reports that people's Mac Pro's are totally silent. Either their computer is indeed totally silent, their hearing isn't optimal, or ambient sounds are drowning out the computer. My Mac Pro is by no means loud, but there seems to be a faint steady purr from it. Very low and probably nothing out of the ordinary, but there. I have the ATI 1900 and suspect that might have something to do with it. Does the fan on the ATI 1900 constantly spin? Is there a program to temporarily turn off the fan so I can see if that is the source of the sound? Do folks just live it it?