Computer Hardware

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. The selections in use now were made in Fall 2017 and have been working well since then (currently December 2021). The main servers mtkent1 and mtkent3 which archive data are Supermicro servers. Typically useful lifetimes for hardware before failure or obsolescence is 3 to 5 years though recently these systems have been more reliable, with only two failures out of about 12 attributed to environmental heat stress. Nevertheless, computers at the telescopes may be smaller modular fanless units where proximity to electronics such as cameras, filter wheels, and focusers encourage short cable runs.

Servers

The Supermicro 1U Intel Xeon servers accomodate 4 hot-swap drives. Assembled and tested systems are availalble from from Servers Direct for a price that is competitve with building one from parts, without the risk.

Workstations

Used for data analysis, given the size of datasets and processing needs of a photometry run, workstations require large memory access, multiple processing cores, and storage of 10 TB or more. We prefer Xeon processors with ECC memory, trading speed of the consumer Intel core series for reliability and lower power consumption of the high end server CPUs. The preferred design for new hardware is an Intel W-1390 Rocket Lake processor with an LGA 1200 socket requiring a W580 motherboard chipset, available as of late 2021 for $540. The Supermicro MBD-X12SCA-5F motherboard which accommodates this processor provides USB 3.0, dual Ethernet, and up to 128 GB of error-correcting ECC memory for $510. This motherboard is in ATX format, and the Supermicro workstation chassis CSE-732D3-903B 900 W of power and only 21 DB of noise accomodates this board for $400. Currently 32 GB of DDR4 ECC UDIM costs $120, and the large 14 TB Seagate Exos drives are $330. With these components, a very useful workstation using 11th generation Intel processing with 64 GB of memory would cost $2220 to build from components.

Used for machine control, simpler, lower cost, and compact mini- or micro-chassis computers are the preferred choice and are being used to replace computers at the telescopes as they age or fail. For these, small HP or Dell systems which are supported by the University's purchasing agreements can be found for less than $1000. HP Elitedesk business computers with a Core I5 processor are available used for $300 with 16 GB of DDR4 non-ECC memory and USB 3.0, perfect for telecope operation, and inexpensive enough to maintain on-site spares. Used HP 800 G3 mini formfactor "desktop" computers with Intel I7, 32 GB of DDR4, and 1 TB NVme SSD plus WiFi cost about $600 in December 2021. The issue with these smaller devices for instrument control is that typically older generations have one Ethernet port, but they are usually run headless in our applications so the display technology should not be a factor in selecting them.

Hard Disk Drives

All new drives are Seagate Exos (formerly Enterprise or Constellation) class SATA drives.

The 8 TB drive was the cost effective choice in 2020 and is being used for replacements and storage upgrades. Allowing 4 slots at this capacity provides 48 TB online, exceeding our current needs for several years. Drives with 14 TB are now available for the price of 8 TB last year, making the 8 TB very cost effective for a workstation.

Note that the commodity Seagate Barracuda line is not as reliable and has had in our uses a unacceptable MTBF of about 2 years. We have not had only 1 enterprise-class drive failure since implementing them in 2012 and an specified MTBF of 5 years does seem to be a realistic expectation in practice.

GPUs and Graphics

Where needed we have NVIDIA Pascal and Kepler architecture GPU cards installed on some processing workstations, but not on the main data storage and web server systems. This technology is evolving rapidly, and for affordable small scale uses the previous generation Quadro series of graphics cards is still useful. New or replacement systems would use the NVIDIA RTX cards, and the RTX A2000 with 6 GB of GDDR6 and 4 display port outputs is available for $700 retail in December 2021.