Originally Posted by Tugela
If the MacPro has a single fan and never makes any noise, all that means is that the CPU/GPU are never being stressed (or they are throttling down under stress due to inadequate cooling), since they are the same CPU and GPU used in conventional PCs and will have exactly the same thermal envelopes and cooling requirements. There is nothing special or mystical about heat exchange where Apple knows some super secret formula that people who specialize in cooling (such as Noctua) don't know anything about.
Of course. And moreover, we are debating now some decibels instead of debating the most important things: performance per cost, OS robustness + ease of use... Let's put things again in order: when you buy a TV, you should expect maximum picture quality in all aspects, and only then you should think about the adjacent things like media player and so on. If when you buy a computer, the first thing is the noise, it means there is a problem... that computer should perform at best and not only in one application, but in general. And of course then the design, noise, power consumption. I don't say these don't matter, but not as the most important aspect.
Edit: very well mentioned Tugela, the throttling is an aspect most people don't know about... Many devices, especially mobile devices, do this silently and since you don't have a comparison, you don't notice. I don't want to say that the Mac necessarily does this, I just say there are a lot of things to be considered. Some of them technical. If it would be a magician, then this world would be full of Macs...