Building a green server

September 13, 2009 | categories: energy, projects | View Comments

Ever since a brief stint as a network administrator in 2005, I've admired the discipline of data backup with undeserved zeal. A little more than three years ago, I decided that I should probably build my own server as a data repository; it could also serve this blog, store my email, and so forth. At the behest of my friend Mike, who once claimed that the massive data breach that Google will eventually suffer will be worse than September 11th, I also kicked my Gmail habit. (Mike has not kept up his end of the bargain, and still uses Yahoo Messenger. Also, he owes me a comic book about penguins.)

Last spring, as we were getting ready to move to Somerville, I had accumulated most of a server, but I didn't really have a good place to put it. Now that we've moved, I have an insulated attic, a moderately dry basement, and most importantly a killer garage. If the house burns down, the data is safe in the garage!

While I am definitely a sucker for an attractive rackmount server with hot-swap drives, I'm even more of a sucker for energy efficiency. I did some research and built what was, at the time, the greenest server I could build with consumer-level components. With the recent release of solid state hard drives, I don't think I can claim to be setting any records, but I think I'm doing pretty well in terms of required cooling power per processor cycle.

The rig:

  • Dual Xeon L5410 quad core processors
  • 1U rackmount case, RM1002T
  • Sparkle 80plus power supply, FSP400-601UG
  • Western Digital low power drive, WD5000AACS
  • Asus DSBV-DX motherboard
  • Two Corsair 1 GB DDR2 667 MHz FB-DIMM
  • Quiet, low power fans (Antec 40mm Ball Bearing Case Fan from ANTOnline through Amazon.com)

Total power consumption started at 131 W with the processors idle, but I was able to reduce it to 102 W by replacing the stock fans with the quieter Antec fans. I haven't actually measured the peak power consumption yet judging by the processor specs, I expect it to be at least 200 W, but probably not more than 250 W.

I tried the server in the poorly-insulated garage this summer, and it overheated pretty quickly. The revised plan is to try the aforementioned moderately dry basement, which affords the additional interesting opportunity of building a geothermal cooling system for it. (Yes, it's a ridiculous idea-- ridiculous and awesome.)

I don't know if I'll ever get around to that, but I'm starting with a water cooling system, which I think is a necessary precursor to a geothermal system. If the water cooling works, I might turn it into a water pre-heater for our domestic hot water heater. I previously calculated our hot water load at around 2 kWh per day, which is an average power of 83 W, less than the average power of the server. We'd certainly lose a lot of the heat along the way, but if I'm going to dump waste heat somewhere, it might as well be into water I want to heat anyway.

(Before you go rushing off to Treehugger.com, note that this "heat your water with your PC" plan is not an economically sound proposition-- heat from electricity is about 4 times more expensive than heat from natural gas.)

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