Which uses more power, the AeroCool Green Home Server or a 40 Watt light bulb? You guessed it, the light bulb looses.
A few hours playing with a Smart-Watt meter hooked up to my home server I came up with some power usage numbers. While idle the Home Server consumes less power than a 40 Watt light bulb. It only consumes a few watts more under normal loads associated with backups and streaming data.
|Backing up *||44 W|
|Streaming music/data **||42 W|
|Under full load ***||68 W (72 W peak)|
The average use over a 24 hour period was just under 0.9 kWh. Huge sigh of relief! After all that guesswork and effort it would be horrible to end up with a system that used more energy than an electric cooker.
The green home server compares very favorably with other systems I was able to dig out numbers for.
These are all two HDD systems with a total storage between one and one and a half terabytes. A typical disk uses about 5-10W so comparing systems with significantly different storage isn’t reasonable. The Green KPC K45 build is from Home Server Hacks, power ratings for a similar KPC based system is in blog comments.
I’ve not included the Shuttle X27 (24W idle and 36W under full load) because it’s not a comparable system. Firstly, Shuttle don’t give any information as to the disks attached to the system they measured so I’d have to assume a single HDD. Adding HDDs has significant effect on power usage ****, about 8W per disk. Secondly, the Shuttle’s Intel Atom 230 1.6GHz gets a PassMark CPU score of 245 compared to the HP MediaSmart’s score of 358 with a 1.8GHz AMD Sempron 3400+. Assuming HP used the smallest processor they could to get the job done then the X27 might not be up to the job. The Atom is certainly borderline as desktop solution and the power hungry motherboard lets it down somewhat in the power consumption stakes too. An AMD Athlon 64 might be a better choice.
The AeroCool WHS uses less power because it uses energy efficient disks and power supply in addition to a low power processor and motherboard. For example, the Seagate drives in the MediaSmart idle at 8W compared to 2.8W for the Western Digital drives.
Is it possible to do better? Yes, definitely. I’m no expert I just assembled a system from the best off the shelf parts I could find. Tranquil PC, based in the UK, make a home server box based on the Atom processor but don’t give power consumption numbers for it. Some of their other systems come in at under 20W idle for a single disk system. Tranquil are worth checking out anyway as they seem to be doing some interesting things in the Green IT space.
What about performance?
How does the performance compare to other Windows Home Server systems? The raw system specs are:
- AMD Athlon X2 BE-2400 Brisbane 2.3GHz dual core CPU
- 2Gb RAM
- 2 x 700Gb HDD drives
Running the PassMark suites gives the following results:
These numbers are comparable to the HP MediaSmart PassMark performance with significantly better CPU performance due to the somewhat over the top Athlon BE-2400. This was a deal at NewEgg, a slightly better choice would have been a 35W rated processor. I think the savings would have been small as it is the overall power consumption of the processor and motherboard that really counts. AMD’s Cool’n’Quiet technology really helps here.
If you have another system and want to share your power usage numbers post then them as a comment here. Remember systems with more or less disks will have significantly different power usage.
In the final post in these series I’ll go over some reconfiguration I did so that the server runs as quietly as possible. With a bit of tweaking you can end up with a near silent machine.
Currently listening to:
Therapy? – Troublegum
* Backing up a single machine over a wired network. Typical incremental backups take under ten minutes.
** Simulated user access by streaming music from the WHS \Music\ share. Two different files to separate instances of media player. Light use in other words.
*** I used the PassMark CPU test suit and disk test suites to simulate heavy load running them multiple times simultaneously while measuring power consumption. The peak figure is the highest power usage observed in a single minute during the tests.
**** HP MediaSmart requires another 8W per drive. See: http://www.hp.com/ctg/Manual/c01276565.pdf page 154.