Measuring Real-World Power Consumption

The Equal Workload (EWL) version of vApus FOS is very similar to our previous vApus Mark II "Real-world Power" test. To create a real-world “equal workload” scenario, we throttle the number of users in each VM to a point where you typically get somewhere between 20% and 80% CPU load on a modern dual CPU server. The amount of requests is the same for each system, hence "equal workload".

The CPU load is typically around 30-50%, with peaks up to 65% (for more info see here). At the end of the test, we get to a low 10%, which is ideal for the machine to boost to higher CPU clocks (Turbo) and race to idle. We use the "Balanced" power policy and enable C-states as the current ESXi settings make poor use of the C6 capabilities of the latest Opterons and Xeons.

vApus FOS EWL Power consumption

We cannot say "mission accomplished", but AMD has made significant progress. 12% to 20% better performance while decreasing the power consumption by 6% to 8% is pretty good. The 95W TDP Xeons are still the performance per Watt champs though. Still, it looks like the Opteron is a decent alternative for some. Power consumption is about 12-13% higher (6376 vs E5-2660), but the performance per dollar is slightly better.

vApusMark FOS SAP S&D
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  • arnd - Wednesday, February 20, 2013 - link

    I have dual Opteron 6344 workstation system, which tends to be either near complete idle or near complete busy, so C states are extremely important to me. The CPU has power sensors that are exposed in Linux using the 'sensors' tool. With C6 enabled, I get the power consumption per socket down to 42 Watts, which still seems like a lot, but disabling C6 made it jump to 104W per socket, when under 100% load it is constantly within 1W of the 115W TDP limit.
    I did not see a significant impact of C1E, neither with C6 enabled nor disabled, presumably because I rarely have cores that are idle for a short period.
    More annoying to me is the lack of S3 suspend mode, the system still consumes around 100W on S1.
  • nevertell - Wednesday, February 20, 2013 - link

    The difference I believe is that you cannot use AES-NI instructions when using Twofish and serpent. I guess that AMD's AES-NI implementation is just slower.
  • JohanAnandtech - Wednesday, February 20, 2013 - link

    Sounds reasonable. The question is then why Twofish and serpent are so fast on the Opteron. They probably scale very well with cores.
  • Yorgos - Wednesday, February 20, 2013 - link

    I've been abandoning tech sites due to stupid posters and internet trolls.
    There is so much addition info and questions in the comments and I don't know why are you letting people ruin that feature from your site?
    You should make a ranking system(similar to /. ) for users, in order to automatically hide someone's comments, so we don't have to double check every time the poster and/or the comment.

    I feel stupid for making that type of comment, also reading specific stupid opinions, below that article.
  • silverblue - Wednesday, February 20, 2013 - link

    I like your ideas, however most of the laugh (or should I say cringe?) worthy comments would be hidden and the entertainment value would be tainted by having to click the Show button all the time. ;)
  • lwatcdr - Wednesday, February 20, 2013 - link

    Or requiring real names.
  • JohanAnandtech - Wednesday, February 20, 2013 - link

    I had meetings and people visiting me, so I could not "baby sit" the reactions. But if you don't react to the offensive message we can delete them. So the best way to deal with th trolls is to ignore. Sooner or later, they will be banned.
  • coder111 - Wednesday, February 20, 2013 - link

    Because some of the people posting here are obviously trolling for Intel and do not bring anything constructive to the discussion.
  • MonkeyPaw - Wednesday, February 20, 2013 - link

    Yes, it is quite pathetic. An ignore button would take care of this situation nicely.
  • iamezza - Wednesday, February 20, 2013 - link

    An ignore button and a report button would be great!

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