Ok, so I bought a base 2009 quad core Mac Pro on Megamacs website on their black friday sale. I love everything about the mac, except that it emits a weird whine when running and even more so when turned off after having been run. It doesn't make the noise when first plugged in, or when it is sleeping. The frequency is probably a little lower than a dog whistle, so some people i've showed it to can hear it and some can't. I have done a lot of testing i.e taking out sticks of RAM, removing video card, HD, etc, and have found that it seems to be the PSU or GPU. My question: Should I try to get a replacement or is it something that is normal with 2009 Mac Pros?