Small and Silent, the Intel Atom
I recently decided to re-visit my Home Theatre PC system and my always on home PC. Recent electricity cost increases have made the $140 per quarter it costs to run my IT systems start to look a bit much. I decided to retire my main PC to more of an “as needed” role with an always on PC being ultra low power consumption. The plan was an Intel Atom D525 PC with 4GB RAM and a solid state hard drive running 24/7 along with my NAS. It was all fine in theory.
The system I built used an ASUS mini iTX motherboard with nVidia ION graphics. Only a handful of the iTX Atom motherboards supported dual digital screens, a non-negotiable requirement. It had a 4GB RAM limitation in the chipset but this was fine for my needs. Two 2GB SODIMM chips fitted in quite neatly and the ultra small Aywun case with external 65W PSU seemed pretty good. It supposedly could accommodate a single 2.5″ hard drive and a slim optical drive. The hard drive mount was fine but the slim optical drive was a tight fit and seemed to distort the drive slightly which made it either vibrate badly or not eject depending on its exact location.
With the system up and running, the meter attached to its power supply was indicating a power consumption of 27W which, based on current prices of $0.21/KWh, equates to around $13AU/quarter, not bad. It was also completely silent with no moving parts and all passive cooling.
Take 1: After removing the slim optical drive and reverting to a USB one for the install, Ubuntu 11.04 desktop was installed. It installed and ran fine and could easily do most of what was asked of it until video playback. HD up to 720p was perfect but 1080p was jerky and not watchable.
Take 2: After Ubuntu not being able to play 1080p, I decided to install Windows 7 instead so I could directly compare the Atom performance against my existing PC. I was not expecting it to play 1080p either and I was right. All other general use was fine although zipping or unzipping large files was, as expected due to a slow CPU, very slow. I was impressed by how fast the Windows shell was, general use was perfectly acceptable, probably due to the speed of the SSD.
I still was not happy due to the lack of 1080p which meant that my experiment could not form the basis of a Media Centre PC which I had hoped it would. I took a step back and decided to rebuild with a fan. I had a brand new model CPU, the bottom of the line Intel Pentium G620 and another iTX motherboard (also with dual digital video) and case from a cancelled order. The Aywun case was too small for the heat sink and fan so I used a slightly larger iTX case with an internal 150W power supply. Unfortunately this also means a power supply fan, a small one, and small fans are noisy. I simply swapped the hard drive across and thankfully it just worked so I didnt need a rebuild. Now I have a much faster (Windows experience CPU index 5.2 up from 3.5 for the atom) small PC, albeit a noisier one that will happily play 1080p. It draws slightly more power at around 32W at rest and the components were actually marginally cheaper than the Atom (full size DIMM RAM chips are faster as well as cheaper too). Graphics performance is actually a bit worse (based on the Windows experience index), the nVidia ION has more grunt than the Intel HD graphics chipset. This is not an issue given that it is not for gaming and video playback is more CPU dependent. The next step will be to remove the tiny power supply fan and try to mount and duct a larger quieter fan instead. Perhaps I can lose the CPU fan as well and simply vent the entire case with a top mounted 120mm Noctua silent fan, it should move more than enough air and be much quieter. Maybe then it will compare to the Mac Mini….but then again, maybe not. The larger case can take a low profile PCIe TV Tuner card though.
Now my home office draws around 130-180W (with screens on) for the NAS, switch, DSL modem, VOIP box, PC and fish tank (yes its on my office UPS) down from the 250-300W it was drawing previously. This is saving around $60/quarter in electricity. Break even will be in less than a year. I get all my equipment wholesale and can claim it as a deduction but can only claim 10% of the home power bill as a business expense. The only other downside is that I now may need heating in the office in winter….