Real-World Power Use

In the real world you do not run your virtualized servers at their maximum just to measure the potential performance, but neither do they run idle. The user base will create a certain workload and expect this workload to be performed with the lowest response times. The general idea behind this new benchmark scenario is that each server runs exactly the same workload and that we then measure the amount of energy consumed. You can find more detail about our real-world power test here.

vApusMark Equal load power test

You get what you pay for of course. The Opteron 4122 is extremely cheap, but these are the most leaky chips that pass the quality tests. Remember the quad-core 2.2GHz will consume at the most 95W (or almost 25W per core) while the hex-core 4170 HE will never pass 65W (11W per core) despite the fact that they are running at almost the same clockspeed (2.1GHz). So the 4170 HE is roughly more than twice as efficient.

Idle Power Use Conclusion
Comments Locked

35 Comments

View All Comments

  • mino - Thursday, March 3, 2011 - link

    While the Wh metric is useful for efficiency evaluation, it is pretty much useless for the exact scenario you mention in the conclusion - power-capped server hosting.

    Please add the load-power numbers to the article.
  • ppokorny - Sunday, March 6, 2011 - link

    And if lower results are better, shouldn't the graphs be sorted so the shorter bars are on top?
  • mfenn - Thursday, March 3, 2011 - link

    People actually use the bezels on Dell servers?
  • JohanAnandtech - Saturday, March 5, 2011 - link

    Only for pretty pictures :-)
  • Lord 666 - Thursday, March 3, 2011 - link

    Trying to hold off on the 5600 purchase hoping that the 5700s are almost here.

    Any idea?
  • duploxxx - Friday, March 4, 2011 - link

    ready to hold off until september - oktober?

    I assume you select an Intel server cpu by default as usual by IT?
  • Ben - Thursday, March 3, 2011 - link

    I know that noise level is a bit of a joke for a "real" server, but I've had customers ask me about installing servers in environments that are less than ideal, where the noise level would be a factor in their decision (such as the corner of an office that is occupied).

    I would be interested in seeing noise levels from these units and possibly a future article focused on a couple units that don't sound like a 747 on takeoff.
  • jcandle - Friday, March 4, 2011 - link

    I've experienced this as well. Primarily ones and twos of units as file and workgroup servers where towers would be ideal. Unfortunately, there are not many options when it comes to the storage. Those FC and SAS 16 and 24 bay RAIDs are virtually all designed for rack and put out their share of noise.

    While it doesn't occur often, some companies are requesting racks operate in the same room as workers; sometimes this has to do with large scientific equipment in the room, or other various lab requirements.

    What I would also like to see in addition to noise levels (dB levels at various distances) like Ben request, is the the thermal load (BTU output of each unit). While some manufacturers give it out and it is often estimated, a real world assessment would be nice. Although I understand this would be difficult if you did not receive a dozen or more eval units; perhaps you have trick up your sleeve.
  • bobbozzo - Monday, March 7, 2011 - link

    You can convert Watts to BTUs easily:
    http://www.google.com/search?q=watts+to+btu
  • ZL1Corvette - Thursday, March 3, 2011 - link

    A 95W chip consuming it's full 95W, 24 hours a day, 365 days a year consumes 832.2 kWh a year. At the GE (http://www.csgnetwork.com/elecenergycalcs.html) average of $.1 per kWh, 832.3 kWh costs only $83.22/year. Going from a 95W chip to a 35W chip only saves $51.19/year. So going with the 4170HE instead of the 4122 costs you $74. You save $24.60 a year. You'd need to keep the chip about 3 years for it to pay for itself. You'll only save a fraction of that per year when only considering the chip consumption, which seems like a safe assumption in the spirit of this article where chips are swapped between the same server.

    I did not use the GE calculator, but it gives the same numbers. A TDP is the thermal output, but I think it's safe to assume that that number is a close representation of the power use of the CPU. Power in = Power out. The only power outs I can think of are the thermal power and the "data" power. I'd find it difficult to imagine the "data" power being significant, and I think that the data would be the same no matter which chip you use.

Log in

Don't have an account? Sign up now