Computer systems that run the telescopes, store data, and provide remote analysis for users are currently built in house from standard components selected for the best performance/price ratio. Starting in the spring of 2014 we will try to document the selections here. Typically useful lifetimes for hardware before failure or obsolescence is 3 to 5 years.
Supermicro 822T-400LPB $424
This is a 2U rack server that accommodates an ATX motherboard with space for 6 hot-swap SATA drives and 1 full height DVD. It includes a single 400 watt power supply.
Corsair Obsidian Series Black 550D Mid Tower Computer Case $117
A large case provides exceptional ventilation, ease of access, and quiet operation. USB3 is brought out to the front panel. The interior has many slots for SATA drives and for two full height DVD drives. If rack mounting is not required, it will work splendidly as a server enclosure especially for systems with GPU cards that require high power. The SATA drive carriers do not use screws, and while the drives are not hot swappable, it takes only minutes to replace one without tools.
The Corsair power supplies have been reliable and are quiet. A typical one in recent use is the TX650 available for about $95.
Power supplies for the observatories have to be quiet, and should be green with high efficiency. Typical lifetimes have been 3 to 5 years, but some supplies from Antec have had premature failure and are not recommended.
The best CPU is selected at time of purchase based on Passmark ratings from this site:
As of September 2014 the preferred selection is an LGA2011 socket Intel Hex Core I7-5820K running at 3.3 GHz for $580. It is available from Amazon and other suppliers at about $380, an alternative to comparable Xeon processors that are about twice the price.
These are supplied without a cooler which is purchased separately. We use the low cost air-cooled Intel Thermal Solution Air $21
It runs quietly, and is not at risk for use at a telescope where there may be temperature extremes.
We have had good success with motherboards from Supermicro. Currently there are more than 10 in service, some for two years of continuous use. We have had three failures in two years. One was in a system exposed to environmental extremes, and a similar one was in a controlled environment. Both failed after a power disruption even though they were on surge-protected circuitry. The problem could have been with the motherboard itself, or due to a spike from the power supply. We have not had a failure with the preferred power supply noted below.
Supermicro X9SRA Xeon and I7 supports 512 GB of DDR3 memory in 8 sockets, and offers 2x PCI-E 3.0 x16, 1x PCI-E 3.0 x4 (in x8), 1x PCI-E 2.0 x4 (in x8), and 1x PCI-32. It is available through distributors offered by Amazon for about $280. This board has built-in audio.
For the LGA2011 socket motherboard, the required memory is 4x or more 8 GB registered ECC DDR3 modules. Crucial currently recommends 8 GB DDR3 PC3-12800 Registered ECC DDR3-1600 1.5V for $110 each.
There does not seem to be the requirement to use non-ECC memory with I7 processors that was in the previous chipset.
All new drives are Seagate Constellation Enterprise class SATA drives. For example, the 2 TB drive currently $150 on Amazon was the drive of choice in 2013:
The 4 TB drive now at $262 would be the choice for new installations in 2014:
Note that the commodity Seagate Barracuda line is not as reliable and has had in our uses an MTBF of about 2 years. We have not had a Constellation drive failure since implementing them in 2012.