Isn't this suppose to be quiet?

Open the case, turn on the PC, get a long cardboard tube, put one end to your ear, move the other end around until it sounds loudest. It could be some case fan gone bad, or the CPU cooler, or the PSU indeed.

Oh thanks for the tip on isolating the sound. I had a problem determining which component it was and was pretty sure it was either the case or psu. As you suggested, it was actually the cpu cooler. Thanks! I'll have to change that now. My next PCs will definitely have a much improved cooling system along the lines of the one I posted earlier.

I knew it! There were two different tones coming from my PC. The higher pitched one was from the CPU, but that's fixed now. The MUCH louder, lower toned sound seems to stem from the PSU.

I have the Antec p180 case, so the power supply is at the bottom, and it's pretty hard to listen closely to it. The power supply doesn't rest completely on the floor of the case,so I could stick parts of my fingers underneath it and wiggle them a little bit. When I did, the loud, low sound responded to my waves. This leads me to believe it's the PSU that's really making the major loud sound.

Like I asked before, isn't this suppose to be a quiet PSU? Some reviewers on newegg seem to think it is... I actually wanna do something about this now since this is, by FAR, the loudest computer in the house...

What's your definition of quiet? Silent?

I'm sure if you ask people what they would consider quiet, you would get many different answers.

Well it doesn't have to be completely silent. But I really find this to be reallllly loud. Like embarrassingly loud. Even though this is the only computer I've ever built, and this is by far the most powerful, I'm sure there's a way to quiet it down. Most computers I encounter are pretty quiet, no matter who the manufacturer is.

Unfortunately I can't give any measurements of how loud it is. But trust me, this is by far the loudest PC I've ever encountered. Not really sure how to describe how loud it is... But trust me, it's loud. You wouldn't want to be working near this thing for a long time.

Here's what I have: 3 hard drives, 2 optical drives, Antec P180B, Antec TruePower Trio 550, AMD Athlon64 X2 4800+, nVidia 7900 GT. I've got only stock cooling, except for the processor, which I have a Noctua NH-U12F and Arctic Silver 5 thermal paste. Even though it isn't make much noise, I'm gonna get a better cooling system for my graphics card. It seems to be running pretty hot. Still would very much like my system to be much quieter than it is.

One of my roommates just confirmed about how loud it is, "it's as loud as my old computer was." Back at home, my brother was teasing me about how it just became the loudest computer. The notebook was the loudest, then I changed the thermal paste, and now it's quieter. Not completely silent, but pretty quiet.