here's a shot of the innards: [tinkafoo.com...]
looks like they banked the RAM so air can circulate around it a bit better than in laptop RAM. Blower-style fans, necessary to do the job in that kind of environment. Intel and others have been thinking a long time about changing the general pc architecture to provide for a better airflow in a smaller enclosure, and if this truly does a good job on airflow, Apple has my full admiration for this design. However, Intel's new designs were never 2" thick. The 25 dB at a meter Apple cites is cooler than my self-built box with a quiet Antec case / 8cm fan / Zalman cooler set at very low RPM's. However, if I used this machine, I'd wanna be more diligent than I am now regarding backups.