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Intel Power

Intel's PowerTOP Extends Linux Battery Life 113

DuracellFan writes "Intel recently released its PowerTOP utility, which builds on work done by kernel developers to make the Linux kernel power-efficient. PowerTOP gives a snapshot of what apps are consuming the most power. The PowerTOP website also hosts patches for several Linux apps and the kernel. In the Linux.com article, lead PowerTOP developer Arjan van de Ven of Intel says that PowerTOP could soon show which applications keep the disk busy." Linux.com and Slashdot are both part of OSTG.
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Intel's PowerTOP Extends Linux Battery Life

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  • by anss123 ( 985305 ) on Thursday May 17, 2007 @11:41AM (#19164085)
    The hardware that runs it does! Typical Intel, trying to shift the blame.

    :)
    • Re: (Score:1, Informative)

      by Anonymous Coward
      Definitely hard disk's activity is not a major contributor to power consumption. CPU usage is. Disks do require some juice to spin up (not that much though), but it's the CPU that makes the difference once the system is up and running. I know because this week I benchmarked precisely this issue: searching a file throughout the filesystem only raised consumption from 0.6 A to 0.65 A, but it went all the way up to 1.0 A when the CPU was at 100% (and at that point running the filesystem search did not raise co
    • Re: (Score:3, Funny)

      by Syberghost ( 10557 )
      Yes, but if we outlaw the manufacture, possession, or sale of hardware, then Linux won't be able to get any, and the tragedy of wasted power will end! Think of the children!
  • by zborro ( 591127 ) on Thursday May 17, 2007 @11:45AM (#19164183) Homepage
    Of course this utility is very useful for developers and for Linux distributors.
    For the average user it is a nightmare.
    • DEAR Developer,

      Your application is costing me money by it using of power!
      Please send a refund check of to . You did not say in the ULA and in the documents that it would cost more money to run.
      Thanks,
      • by vux984 ( 928602 )
        Despite the humour/sarcasm in your post... i think in some cases the developer/vender should clearly indicate that it will cost additional money in electricity to run. And it should be -clear- not hidden in some EULA.

        Projects like "folding@home" for PS3 which can add $200-400 a year to your electric bill.

        Consumers should be made aware of that, before donating their 'free computing time'. Its not free.
        • by Arkaic ( 784460 )
          I would hope that most people who use appliances realize that they are paying for the electricity to run them. TANSTAAFL.
          • by eddy ( 18759 )

            But this isn't a boolean value, you can be almost certain that your typical user do not understand the huge difference between full load and idle in power consumption and therefore money.

        • My fridge did not clearly indicate that keeping my food cold would cost me money in electricity. The hid that fact away in the "manual." I'm outraged.</sarcasm>

          If people aren't aware that making an electronic device do work uses more electricity, it's their issue. I, for one, am tired of people putting the blame on others for not knowing the blatantly obvious.
          • by pricedl ( 47059 )

            My fridge did not clearly indicate that keeping my food cold would cost me money in electricity. The hid that fact away in the "manual." I'm outraged.

            Really? Every fridge I've ever seen in a store has a great big sticker on the front with a dollar amount for the expected electricity cost.

            If people aren't aware that making an electronic device do work uses more electricity, it's their issue.

            Usually, a fridge or freezer uses less electricity when it is full than when it is empty. So, the more work you

        • I'm a little skeptical about that value (but willing to be convinced). I only pay about $300/year for electricity overall. Of course, I don't own a PS3. However, I do have a refrigerator and an air conditioner (as well as other devices that use electricity).
          • I only pay about $300/year for electricity overall.

            Dont you mean $300/month? And if its really $300/year where do you get your electricity from?
            • My last 6 power bills add up to $127.10. Of course, that doesn't include the hottest months. I can't view back further than 6 months, or otherwise I'd provide a more exact number. I do know that my power bills don't go up that much during the summer, so I just guesstimated at the $300 value. No doubt it helps that I live in a 1-bedroom apartment and not a house.
          • Well, a 24/7 PS3 (or folding@home high end computer) can take as much energy than all the rest combined, _if_ you dont use AC and dont heat electrically.

            Quick caluclation: PS3= ca 200W. 2.5 kWh/day, ca 850 kWh/ year. con be everything from 50-300$, depending on your local energy costs.
            • Even though I do use AC (although sparingly). My heat comes from the radiators, and hot water comes from our apartment complex. (I.e., it's included in the rent.) Also, my stove/oven uses gas. Just throwing all of that out there since I seem to have generated a little bit of skepticism with my original claims.

              Would anyone not notice (other than rich people with mansions, etc.) an increase of 2.5 kWh/day? Even if you use 10x the electricity that I do, that'd be a 10% increase.

          • by vux984 ( 928602 )
            I've posted this before on slashdot but here's a quick breakdown:

            The PS3 is reported to run 220W when running folding@home.

            In, for example, New York, the average residential cost of power in 2006 was 16.86 cents: (http://www.ppinys.org/reports/jtf/electricprices. html)

            So 220W or 0.22kW x .1686 $/kWh x 24h/day x 365days/year is: $324.93 per year.

            New York is on the high side for the US, but not remotely the highest. And prices in Europe tend to be considerably higher.
            Additionally, the rate tends tend to be ti
            • Based off your 220W figure, that results in approximately 158.4 kWh per billing cycle. Yowsa. folding@home would appear to be a good cause, but I agree that it would be nice to know up front how much you're actually "donating" to them. OTOH, if you don't notice an extra 158 kWh on your power bill, then perhaps you're not really going to care that much.
              • by vux984 ( 928602 )
                folding@home would appear to be a good cause

                I think it is.

                but I agree that it would be nice to know up front how much you're actually "donating" to them.

                That's the crux of it. $200-400 is not a trivial amount of money. And personally, even though I think folding@home is a good cause I think if I'm going to 'donate' that much money, I can think of other causes I think are more worthy... and I'll get a tax receipt too.

                OTOH, if you don't notice an extra 158 kWh on your power bill, then perhaps you're not reall
                • Of course, he's no Joe Six-Pack, either. He's definitely where I got most of my nerd genes from. Yeah, I suppose I was thinking too much from my own no-child, low-power consumption perspective, though. For me, it'd literally double my power bill. Trust me, I'd notice.
      • by DrYak ( 748999 ) on Thursday May 17, 2007 @12:05PM (#19164549) Homepage
        DEAR User,

        Sorry but you're mistaken.

        You actually discovered our latest feature.
        You haven't read about it yet, because we were developing and testing it until very recently, and we didn't want to speak to early about it.

        We, as developers conscious of their travelling users, that have so much time that they need to work as they are in the train, have though of YOU !

        As such we present you our latest feature :
        WE GIVE YOU THE POSSIBILITY TO COOK YOUR DINNER ON YOUR LAPTOP (so you can do even more important things during the time you're commuting, which will leave you more free time when you reach your destination !)

        Alternatively, you can also use our application on your laptop as AN INCREDIBLE AND COMPACT LAP-WARMER !!! For all those long commute during winter.
        (DISCLAIMER : Warning, do not use with Batteries manufactured by Sony).

        Thank you, wish you enjoy our brand new features.

        - The Dev team.
  • The blurb says that the tool told him to disable beagled which he did and he was duely impressed when the number of wake ups per second dropped. However the actual watts used went up. Thought the point was to save power?
    • by vidarh ( 309115 )
      You're assuming that nothing else at all changed on the system to add to power consumption. Such as activity (both CPU and disk) when he shut down Beagle for example.

  • I have a server at home that I'm about to upgrade the kernel on, and I would very much like to have it as energy efficient as possible... but I worry about stability. Is NO_HZ safe?

    • Re: (Score:2, Informative)

      by VON-MAN ( 621853 )
      Doesn't really matter. You can make yourself a custom kernel just to check your apps and services with NO_HZ. Then when you've identified the misbehaving processes you can fix them and start using your old kernel again.
      • Re: (Score:2, Interesting)

        by eddy ( 18759 )

        Sure, but I was thinking more like "I went with NO_HZ and then apparently the initialization code for my controller freaked out and ate my RAID-set" type problems, not "The SSH daemon didn't start."

        • by VON-MAN ( 621853 )
          Now that IS serious. Have you read anything that would suggest such problems exists, or is this simply the most terrible thing you could think of?
          • by eddy ( 18759 )

            Don't panic! That was my worst-case scenario. They only thing I've read about it was, and this is from memory, a post I believe from Linus where he mentioned in passing that the inclusion of this patch was "difficult" which I took to mean "touched a lot of stuff and took a while to get right" which I then interpreted as "maybe I should wait and see".

            The whole "it's in the stable kernel, therefore don't worry"-thinking doesn't carry a lot of weight with me, especially not since the whole concept of "stabl

            • by VON-MAN ( 621853 )
              Never panic. Especially not around computers.

              The real testing being when this hits distros. I'll probably try it later, maybe even wait for .22
              You said it's your home fileserver that you wanted to try it with, so i wouldn't expect disasters on your metal. But of course, if you want to be absolutely sure there let the masses test this and use it later.

              I don't mind a bit of excitement, now and then.
            • by gmack ( 197796 )
              Generally my policy is to try things on my PC first and then the laptop. Once I'm sure a feature is stable then I try it on my server and my customer's servers. If your worried about the feture I would suggest waiting until 2.6.22 but most of the complaints about it on the kernel mailing list involved the machine just refusing to boot during the rc cycle so it should be safe.
    • by Ant P. ( 974313 ) on Thursday May 17, 2007 @01:36PM (#19166367)
      I'm using NO_HZ on my P4 desktop. It was horrible in old patches, but the version in the mainline kernel (>= .20) is solid as a rock.

      I gave the powertop thing a try the other day. Seems the worst offender on my machine is MPD, even when it's not doing anything.
  • by mpapet ( 761907 ) on Thursday May 17, 2007 @12:05PM (#19164551) Homepage
    C'mon what are we talking about here, a few minutes? AFAIK, better power savings comes through a good acpi config, which I don't see a whole lot of discussion on.

    My guess is where this kind of thing would make a dollars/cents difference is in the NOC. But this kind of detail isn't very sexy or very high on most NOC operators radar.
    • Re: (Score:3, Insightful)

      C'mon what are we talking about here, a few minutes? AFAIK, better power savings comes through a good acpi config, which I don't see a whole lot of discussion on.


      It could mean as much as an hour or two, depending. The less the CPU sleeps, the more power it consumes. The more the HDD gets accessed, the more power it consumes. ACPI doesn't buy you much if your CPU is constantly running at full clock and your HDD is always spinning.
    • How about hours? (Score:5, Informative)

      by eddy ( 18759 ) on Thursday May 17, 2007 @12:12PM (#19164659) Homepage Journal

      Success Stories [linuxpowertop.org]

      "With PowerTOP, I managed to increase the battery life of my Panasonic R4 laptop from 4 to almost 7 hours" -- Keith Packard, Principal Engineer at Intel

      Guess you could accuse him of bias...

      • Almost 3 hours, huh? That's pretty good! I wonder how much of this stuff is common sense, though. For example, killing beagled is pretty obvious because of what it does -- it constantly indexes stuff in the background, consuming power through HDD and CPU cycles.
        • Re: (Score:3, Informative)

          by eddy ( 18759 )
          If you just read the site (it's very small) you'll see that there are many no-obvious [mozilla.org] things you can detect with it. I personally do however consider it primarily a developer tool, but that might change. But even non-coding users can find out that the CDROM automounting polling is waking the CPU a lot, and disable that in battery mode, etc.
      • Re: (Score:3, Informative)

        by caseih ( 160668 )
        Kieth was well-known in the Linux world before he went to work for Intel. He's largely responsible for the composite X extension, and even the Xorg fork. I also believe he had some influence on the technology responsible for making compiz work. I remember using an early version of his experimental, fancy rendering X server. Also, notably, he created the kdrive mini x server for embedded environments. So he's got a lot of low-level linux experience.

        Getting 7 hours of battery life is indeed impressive.
    • Re: (Score:3, Interesting)

      by jandrese ( 485 )
      That depends. Laptops are saving power because presumably they're idle most of the time and this program can tell you which processes behave badly while "idle" (by, say, polling the HDD for no good reason). On a server presumably your machine spends very little time idle (since you're serving stuff), so there isn't much opportunity for power savings from an application like this.
      • by Handyman ( 97520 )
        Well, that's not entirely true. Many servers do spend a lot of time idle. Take for instance company internal servers -- they spend HUGE amounts of time idle, about 24 - 8 = 16 hours of each day. OK, subtract one hour for backups. Still, that's a huge amount of power being wasted on an idle machine. Also, there are a lot of web servers that serve country-specific sites. These machines may not be idle enough to spin down their hard drives, but they sure are idle enough to save some serious CPU power. They wou
    • Re: (Score:3, Insightful)

      C'mon what are we talking about here, a few minutes? AFAIK, better power savings comes through a good acpi config, which I don't see a whole lot of discussion on.

      Do you even know what ACPI is? Have you read the link? (clearly not)

      No matter how well your "acpi config" is done, if you've a process eating 100% of the cpu power all the time, your batteries will last less than a compuer with no ACPI that it's doing nothing.

      IOW, even when your "acpi config" is good, you can save a lot of power. Not minutes, but e
      • by mpapet ( 761907 )
        if you've a process eating 100% of the cpu power all the time

        1. It's not so much acpi, but cpu frequency scaling I should have mentioned. Sorry, wrong terminology.

        2. My point is that the unsexy work of sophisticated uses of frequency scaling would probably help more on a laptop. I'm estimating the most power consumption is the lcd panel followed by the cpu which is where the frequency scaling helps.

        3. I run a bunch of servers and a storage array and it would be great if the disks would run at lower power
    • Re: (Score:3, Interesting)

      by Just Some Guy ( 3352 )

      My guess is where this kind of thing would make a dollars/cents difference is in the NOC. But this kind of detail isn't very sexy or very high on most NOC operators radar.

      Our FreeBSD servers auto-throttle their CPU speeds down when idle. The average runtime on our monitored UPS has gone from 60 to 75 minutes. Even if electricity were free, and even if air conditioners were free, and even if we didn't care about wasting energy for no good reason, that still means we have 15 more minutes to get the genera

    • Re: (Score:3, Informative)

      by Spoke ( 6112 )

      C'mon what are we talking about here, a few minutes? AFAIK, better power savings comes through a good acpi config, which I don't see a whole lot of discussion on.

      The biggest and easiest power savings come from CPU frequency scaling (if your processor supports it). Linux has long done a good pretty good job of putting the CPU to sleep and low power states when it can.

      For older Athlon/Duron processors installing/running athcool makes a significant difference in power consumption (as long as it runs stable on

  • From TFA:
     

    In the screenshot, the laptop isn't doing very well. Most of the time the processor is in C2, and then only for an average of 4.4 milliseconds at a time. If the laptop spent most of its time in C4 for at least 20 milliseconds, the battery life would have been approximately one hour longer.

    Wow. That's really cool. I love how open source allows you to tweak your settings down to the core like this - and Intel is the company that made it.
  • My results (Score:5, Interesting)

    by rg3 ( 858575 ) on Thursday May 17, 2007 @12:49PM (#19165375) Homepage
    I have just tried the thing. I achieved less than 20 wakeups per second when my KDE desktop is idle, but learned a few things on the way. For example, by using a USB mouse instead of the laptop touchpad I am unable to reach state C3. It's reached when I unplug the mouse. I suppose I'll have to put up with it, because I can't stand the touchpad. On the other hand, I used to have KMail opened in a second virtual desktop to check for mail every 60 seconds, but I discovered that the bastard was waking up twice a second for no apparent reason, so I have started to use Korn (the mail check systray thingy). There are still some applications that wake up for no reason apparently. For example, why does klipper wake up once per second? And the same goes for kwrapper. I don't even know what that is. Can somebody explain in detail? Google isn't very specific about it.

    But yes, the application is very interesting. Sorry, Intel, my laptop has an AMD processor. The next one will be Intel, with an Intel graphics card and an Intel wireless card. I promise. :P
    • From the man page of kshell ( link [ca.infn.it]):

      kwrapper tries to make the application look like it was actually started directly and not via kdeinit. Like kshell it passes application name, arguments, complete environment and current working directory to kdeinit.

      Additionally it

      -
      tries to redirect application output to the console from which kwrapper was started
      -
      waits for the application to finish (but does not return its return value)
      -
      passes most signals it gets to the process of the started app
      • by rg3 ( 858575 )
        Thanks for the info. That's what I had found on Google, but it's not clear to me what KDE uses it for. I don't think that type of application needs to wake up once per second.
        • Sounds like it's an app-launcher / wrapper-to-KDE. The need to wake up periodically is probably to check for signals, including if the program has finished. As the man page states, it passes input IT receives (i.e. the kwrapper receives the inputs and passes them to the program it was used to launch), tries to pass output from the app to the console (nay, konsole) and waits for the app to finish. It seems that very few programs should be launched with kwrapper unless the input-passing or term-output is rea
          • by rg3 ( 858575 )
            None of those three activities you mention need active wait really. For example, waiting for a process to finish is a matter of running wait() or waitpid(), which blocks until the process finishes. Waiting for a signal can be done by setting a signal handler and running pause(), for example, or by blocking the signal and running sigwait(). Waiting for other input (like in standard input) is also a blocking procedure. All those activities can be handled without waking up every second. If you have to do sever
  • "PowerTOP gives a snapshot of what apps are consuming the most power."

    Cool, now we'll see things like "New Notepad-lite with reduced power usage!" Maybe "new, less-bloated app" won't be far off. I can dream.
  • arts patch (Score:3, Interesting)

    by IceFox ( 18179 ) on Thursday May 17, 2007 @01:06PM (#19165709) Homepage
    A KDE developer used it and made a patch for arts on his blog [homelinux.org]. I look forward to what other developers find and fix.
  • So who is going to write the daemon that shuts down various services like beagled or reconfigures running applications (i.e. turns off animated cursors) when running on batteries? Of course, switching everything back on when line power is provided would be a must.
  • gnome-power-manager as the biggest power hog on the system.
  • by PPH ( 736903 ) on Thursday May 17, 2007 @03:05PM (#19168247)
    ... its a tie between my USB-powered arc welder and all the kewl blue LEDs.
  • So, nobody has made a "Power Bottom" joke yet?

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