Continuing on from my previous post one other component I have included (that I didn't mention previously) is a SOtM Fan Noise Filter. While the Motherboard I have used has a low power fan-less Atom processor the case itself does include a small silent fan which I have opted to run as it's noise factor is 0 (at least at present). As I had purchased a SOtM Filter (in anticipation of having a CPU fan to deal with) I've inserted this into the case fan power feed - it may not be making a huge contribution but then again it might just be helping, and as I had it on hand it might as well do something!
Talking fan-less Atom CPU's & boards one thing to watch for is ventilation - while the Silverstone case I used (the LC19) has a decent amount of ventilation in the upper surface (about 50% of the case lid is perforated, including virtually all the area above the motherboard), it is reliant on a reasonable volume of air space above for dissipation. I initially had it with just 20mm or so of clearance above and this was inadequate - the core temperatures were usually around +65°C initially (max safe temp is +75°C) however once in the constrained rack space these rose to around +69°C, and once I started ripping a series of Music DVDs they rapidly rose to the limit (and even over, one of the cores sitting at +76°C for some time while ripping DVDs). The heat dissipation was very reluctant even after being idle for several hours, only dropping 2-3 degrees. However once I was able to rearrange my rack to increase the height of the air space above the server to about 7cm the temperatures rapidly plummeted back to their norm, and even while in use happily were sitting around +64°C to +66°C again within about 20 minutes - highlighting how the fan-less CPU's are reliant on the appropriate case ventilation with appropriate space above for their heat sinks to work efficiently.
