Originally Posted by solipsism
If you were going to make a case for a hackintosh being "orders of magnitude cheaper" per Ghz than a Mac Pro I'd give you that, but to say it's "orders of magnitude quieter" than a Mac Pro you'll have to back that statement up. What testing have you done.
Anecdotally, my HP Media Smart home server is the only noisy 'PC' I've owned in several years. I never once herd my Mac Pro. It's designed to run quietly. Have you ever owned or used a Mac Pro?
I briefly owned a 2008 Mac Pro, there are two of mixed vintage in the house I share and a friend does pro video on a cluster of Nehalem machines which I've examined (and admired) thoroughly as preparation for building cost-effective hackintoshes without cutting corners.
Having experience with audio, I can say with a modicum of confidence that as quiet systems go (and the Nehalem Mac Pros are very
quiet for an off-the-shelf machine), the system I built is orders of magnitude quieter, at a guess by around 10-15dB at a distance of 30cm from the side of the case.
The problems with the Apple machines are: a relative crapload of fans (one in each CPU heatsink, two at each end of the CPU chamber, one in the expansion card chamber, one in the PSU and another if you've got a reasonably powerful graphics card), no sound-deadening case lining and fairly rigid hard drive mounts. The fans are also PWM-controlled variable-speed, ramping up (and I've heard them get pretty loud) if things get toasty.
The system I built has a grand total of two high-quality 120mm fans, permanently under-volted to spin at a constant rate of 500rpm, which is difficult to discern even with your ear next to the fan naked. They will never spin any faster regardless of CPU load. The whole case is also lined with thick, dense bitumen based material, adding substantial mass to the case panels and absorbing any high frequency bearing noise from the fans and hard drive. By far the loudest thing in the whole machine is the single hard drive, and it becomes inaudible if you move your head further than a foot from the rear of the case.
Temperatures are not an issue, with all cores loaded overnight in a room at 25C, the max CPU temp is around 55C.