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Ubuntu's Power Consumption Tested

RedDragon writes "Ubuntu 7.10 is due out on Thursday, October 18, and in addition to desktop 3D effects, GNOME 2.20, and other features is the use of the Linux 2.6.22 kernel with the tick-less (CONFIG_NO_HZ) kernel feature. But does this mean enhanced power savings when compared to past Ubuntu releases? Phoronix tested Ubuntu power consumption looking back 2-1/2 years at the six Ubuntu releases from Ubuntu 5.04 to the yet-to-be-released Ubuntu 7.10. Testing was done when the system was idling and then under load, and when the Lenovo notebook was powered via the battery and then again with the AC adapter. The Pentium M CPU temperature was also monitored. While Ubuntu 7.10 does include the tick-less kernel feature, more daemons and processes running by default on these modern Ubuntu releases is actually causing an increase in power consumption."

10 of 330 comments (clear)

  1. Is this supposed to be a surprise? by cleatsupkeep · · Score: 5, Interesting

    I'm confused - don't computers now use more power then they used to? Because of new software and being able to do more powerful things?

    I mean - Vista will use more power than Windows XP, OS X will use more power than Mac OS 9.

    Or is there a fundamental flaw in my logic that I'm missing here?

    1. Re:Is this supposed to be a surprise? by Cruicky · · Score: 5, Interesting

      It would have been nice if the article confirmed that the HPET timer was active, which I believe is rather important for the tickless kernel to work most efficiently.

    2. Re:Is this supposed to be a surprise? by SuperQ · · Score: 5, Informative

      Does this answer your question?

      $ grep HPET /boot/config-2.6.22-14-generic
      CONFIG_HPET=y
      CONFIG_HPET_MMAP=y
      # CONFIG_HPET_RTC_IRQ is not set
      CONFIG_HPET_TIMER=y
      CONFIG_HPET_EMULATE_RTC=y

      $ dmesg | grep hpet
      [ 8.328261] hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0
      [ 8.328266] hpet0: 3 64-bit timers, 14318180 Hz
      [ 0.744000] Time: hpet clocksource has been installed.

  2. Other OSes? by p0tat03 · · Score: 5, Interesting

    I'd be more interested in seeing how Ubuntu's power consumption stacks up against Windows and MacOS...

    1. Re:Other OSes? by tomee · · Score: 5, Interesting

      I agree. There also seems to be no info on whether they used the 3d-desktop stuff. I would imagine that that would have a much greater impact on the power consumption, and it would be interesting to see some data on that.

  3. How to test the power comsumption of Linux by Anonymous Coward · · Score: 5, Funny

    1. Run the particular distro.
    2. Make sure the power cord is long and in the open.
    3. Allow a penguin to chew through the cord.
    4. Measure the distance the penguin flies after chewing into the cord. This will give you some idea of the power usage.
    5. Well, don't let that penguin go to waste! BBQ and teriyaki are great ways to make penguin. Personally, I prefer General Tso's Penguin myself.

  4. Re:Snazzy effects by F-3582 · · Score: 5, Informative

    Rest assured, it takes you four mouse-clicks to disable them. Every tried that under Vista?

  5. Sig Fig nitpick by Anonymous Coward · · Score: 5, Insightful

    TFA doesn't specify error bars, which of course makes the results somewhat dubious. They list numbers to two decimal place accuracy (e.g. 48.00), but since all the numbers end in .00, I'm guessing those decimal places are not significant. In other words, the number are only good to within +/- 1 or +/- 2 or something like that. Considering that they are trying to compare numbers that are quite similar (27 to 33), their conclusions may not be reliable.

    When comparing numbers, an estimate of the error is crucial. If the difference between two measurements is smaller than the error, then you cannot meaningfully say they are different.

  6. More features - Same power by Cryophallion · · Score: 5, Insightful

    Actually, I think it is rather impressive that 7.10 (which has eye candy on by default) has slightly less power consumption than 7.04 (no eye candy by default).

    In other words, they increased features while decreasing (generally) power consumption. While it seems to be only about 1 or 2 watts lower (excepting battery idle where it is slightly higher), we are only talking 3-5 watts difference over 2.5 years of updates. In fact, it went down 4 watts using ac idle compared to 5.04, which I am sure had far fewer daemons/features.

    Some of this may be better code etc. However, I think we should be giving the people who have been doing the coding here major Kudos for doing getting the most out of our computers (whereas MS wants us to quadruple our ram to use eye candy, they are doing it with the same amount of ram standard 4 years ago on a desktop, and keeping power down). I don't even want to think of what Vista must use in power.

  7. Re: I can believe that by Dolda2000 · · Score: 5, Informative

    I don't know what it is there for, but according to this description, it doesn't sound like it is something that a vanilla, desktop installation would want on there. That's not the trackerd you're looking for, though (for future record: You may want to try dpkg -S /usr/bin/trackerd, followed by dpkg -s $PACKAGENAME to find out what it is). Trackerd in the latest Ubuntu is a desktop search thingie, similar to Spotlight or whatever the Vista thing is called. I'd imagine that the load you were seing after about ½-1 hour of use was that it was still busy indexing your preexisting files. Once it gets past that, it gets quite calm in my admittedly limited experience.

    The approach to background processes should be the KISS. On a vanilla desktop installation, only the barest set of such thing should be on there. If that's what you want, maybe you shouldn't be using Ubuntu?