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Power IT

Five PC Power Myths Debunked 551

snydeq writes "Turning off PCs during periods of inactivity can save companies between $25 and $75 per PC per year, according to Energy Star, savings that can add up quickly for large organizations. Yet most organizations remain behind the times on PC power management, in large part due to common misperceptions about PC power, writes InfoWorld's Ted Samson, who outlines five PC power myths debunked in a recent report from Forrester, ranging from the energy savings of screen savers, to the energy draw of powering up, to the difficulties of issuing patches to systems in lower-power states."
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Five PC Power Myths Debunked

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  • by zippthorne ( 748122 ) on Friday December 12, 2008 @10:44AM (#26090001) Journal

    Myth No. 1 really hurts to read. I'm not sure there is a single instance there where the units of power and energy are used correctly.

  • by JeffSpudrinski ( 1310127 ) on Friday December 12, 2008 @10:54AM (#26090133)

    I agree that you can save power with low-power (standby) modes on your PCs.

    However, as a network admin as a mid-sized company, I also have seen loads of frustrations where PCs (both laptops and desktops) don't come out of power save mode cleanly, requiring a reboot. Wake-on-lan is also a great concept, but also pretty buggy ( my limited experience trying to implement it). We also have issues where our client systems are using network applications with license pools (e.g. database applications or CAD packages). When a user leaves one of these applications open, then the PC goes into power save really freaks out when it comes back out of power save mode since the license server thought the system had released the license, but the client still thinks it has a licens in use. This situation usually results in the need to reboot, which frustrates the users to no end.

    I set all of our PCs here to lock and send only the monitor into low-power mode after 20 minutes or so. Then we don't have the problems with coming out of power save mode and having locked up or frozen applications (especially the aforementioned network applictions), but still save a good bit of power by allowing the monitor to be turned off automatically.

    Anyone have any idea what percentage of power is used by the monitor versus the PC itself? I don't have a clue, but I'd bet it's a pretty good percentage. There's also probably a big difference between CRT monitors and LCD monitors...again, my gut feeling, but I can't cite any numbers.


  • S3 Suspend to RAM (Score:2, Interesting)

    by Tynin ( 634655 ) on Friday December 12, 2008 @10:57AM (#26090159)
    S3 is such a nice feature. My wife never powers down her computer all the way any more, just suspends it to RAM, in seconds, and the boot up is just as fast. That said, the last 2 motherboards I've used, while technically support S3, are unable to suspend without immediately waking up. I've done my homework on it and no matter what I do, it won't stay suspended (unplugged all USB and network cables, only had a monitor and ps/2 keyboard and it still doesn't suspend). Does anyone know of any websites that have a list of motherboards that properly implement S3 mode?
  • by Nursie ( 632944 ) on Friday December 12, 2008 @11:04AM (#26090287)

    NSLU2 + bus-powered USB drive + debian + torrentflux-b4rt

    Max 10W drain, with one drive it's nearer 5W. Add in ushare and you have a low energy box that has a web interface for torrenting stuff and can stream the results to your xbox. All for $60 (or so) and the price of the drive.

  • by JustinOpinion ( 1246824 ) on Friday December 12, 2008 @11:08AM (#26090359)
    Thank you!

    This is an "intangible" that is too often forgotten. I have my computer set up the way I want it. Not just in terms of installed programs, but in terms of what applications are open and how they are arranged on screen (and how they are internally arranged: e.g. toolbars, options, documents). This arrangement conveys information to me in much the same way that a "disorganized" desk actually contains important information for the user (the spatial arrangement of papers and piles allows the user to access information rather efficiently).

    This means that every shutdown or reboot forces me to reorganize (as if someone tosses all the papers off your desk). Yes, sleep/hibernate modes should retain this information, but a full reboot generally destroys it. KDE remembers a lot about what programs were open and where they were placed, but still some information about window sizes, options that were set, and documents that were open, gets lost.

    What I would like (and now I'm dreaming off onto a tangent, I know) is to have an OS/GUI that was able to properly save the "state" of all open programs. Not just a memory dump, but an proper save of what applications were running, what options were set, how toolbars were aligned, etc. This would allow me to restore the proper state after reboots. It would also allow to close and open "task groups", where each "task group" would contain a variety of tools/apps/documents, all arranged on screen in a particular way. (E.g. I open the "website editing" task-group that I had open last week, and it opens all my tools and text editors, just the way I left them, launches a new Firefox window with tabs properly populated like they should be, etc...)

    Bringing this back to the energy-savings issue, consider this user-complaint from TFA:

    The Forrester report does acknowledge that end-users have very little patience for downtime.

    Users shouldn't have to deal with downtime. However why can't our modern computers have some simple logic: like IT loads a policy onto all computers that if they are idle for >1 hr after 6pm, they automatically save their state and shutdown; and then automatically bootup/wake-up and restore state at 6:30 am (exact times would of course be tuned based on the particular business or even user). For 99% of users, they would never see their computer turned off, yet it wouldn't be running uselessly all night long. All we would need is a robust way to save the computer state. (For that matter, why don't companies currently do this using the sleep/hibernate modes?)

  • by thesolo ( 131008 ) * <> on Friday December 12, 2008 @11:09AM (#26090377) Homepage
    Mod parent up. My current setup at work, which consists of two desktop machines (one Vista, one Ubuntu) and one laptop (OS X), takes 20 minutes to get everything up & running from being shut off.

    It takes a lot of time to get them booted, load the various pieces of development software, open the projects up, find the pieces of code I need to work on, etc. Furthermore, the Vista PC (brand new Dell XPS) has annoying problems with being put to sleep; for example, when you wake it up, the audio stops working. Only a reboot fixes it, which means even more downtime.

    And then there's Automatic Updates from Microsoft, that like to reboot your computer without your say in the matter...except that the Vista box doesn't reboot properly afterward.

    Honestly, I'd love to hibernate them properly, but it doesn't work, and shutting them off is not an option.
  • Re:Winter (Score:2, Interesting)

    by Hurricane78 ( 562437 ) <deleted.slashdot@org> on Friday December 12, 2008 @11:41AM (#26090925)

    Mine actually did. Unfortunately I was sleeping in the room next door.

    Why do I know this? Because one of the girls actually told me about the hot girl-on-girl action (rubbing pussies against each other), and showed me the scratches from fingernails on her back.

    If only I would have left the web cam recording it, or gone to the toilet at night...

    The worst thing is that I do not even make this up. *cries*

  • by mrchaotica ( 681592 ) * on Friday December 12, 2008 @11:45AM (#26091003)

    Try a Mac. One of the things that initially impressed me most about my old iBook G4 was that sleep actually worked. (I have a Thinkpad X60 tablet now and while sleep mostly works, I never know whether it's going to suspend to RAM or to disk.)

  • Re:Winter (Score:5, Interesting)

    by MrSteve007 ( 1000823 ) on Friday December 12, 2008 @12:01PM (#26091261)

    The EPA awarded my company with one of their top awards this year for improvements to our facility, and energy efficiency. Overall we cut energy consumption 50%, but also used our energy more smartly, including a dedicated ducting system from our server room to the building entrances. We calculate that our servers put out between 8,000 & 12,000 Btu an hour. Most of our overnight heat now comes from the servers (which have to be on 24/7 for off site access), and we've reduced our server air conditioning loads by 80% annually. We're now beginning to implement this change into bank designs.

    In almost every application, it's ideal to shut off computers when not in use, but there are some business based situations where it makes sense to better harness waste heat from electronics, instead of fighting it with energy intensive air conditioners. []

  • Re:Typo? Pshaw! (Score:5, Interesting)

    by systemeng ( 998953 ) on Friday December 12, 2008 @12:41PM (#26091893)

    Unit errors are generally a sign in technical fields that a report hasn't been well thought out. No engineer proofreading this would have missed such a blatant error which means that an engineer didn't proofread it.

    If an engineer did not proofread it, an engineer did not likely do it. Therefore, the content of the article was likely done by an incompetent hack and charging $279 for the report is a way of hiding the fact that it was written by a hack.

  • by gstoddart ( 321705 ) on Friday December 12, 2008 @12:47PM (#26091979) Homepage

    Good insight. With my salary a 15 minute loss would be $3000 lost per year. However shutdown time is not something I have to sit and watch, and it doesn't really take 10 minutes to bootup

    No, but by the time I open my source-coded control program, my mail, my IM client, the document I was editing, my development environment, my trouble ticket application, my folders to check the nightly builds, and all that other crap, this really would be many minutes of wasted time for me each morning.

    An IT mandated policy of turning off the machine every night is going to be about as useful to me as scheduling the antivirus to run at 9am and chew 100% CPU time until noon. This really did happen in our shop, and after they almost got lynched because the AV was eating our entire mornings, they recanted. For a few hours each morning, literally everyone's machine was completely unusable; people were NOT happy.


  • Re:Typo? Pshaw! (Score:1, Interesting)

    by Anonymous Coward on Friday December 12, 2008 @12:52PM (#26092031)

    How about 'they got it backward and just made a typo'?

  • by kimvette ( 919543 ) on Friday December 12, 2008 @12:52PM (#26092033) Homepage Journal

    Ah, but that is immaterial. Employers should just dock their employees for the boot time. See []

  • by MrCrassic ( 994046 ) <deprecated AT ema DOT il> on Friday December 12, 2008 @12:56PM (#26092103) Journal
    Why can't computers have timers automatically configured to turn themselves on before the user enters the office?

    This is what I did in my last position, and it worked well. I was due to come in at 8:30am, so I turned off the computer when I had to go (or scripted a time for it to turn off if there was a process running), and configured the BIOS alarm to wake the computer up at 7:30am every weekday. Worked every time; the only thing I had to do was log in, but since credentials are cached, all of my background programs were started before I even had to type my user name.

    The only caveat is that I can't do this for Thinkpads for some strange reason.

    Lots of people are intolerant of even rebooting their computer during the day, but don't realize how infuriated they would get when their computer starts acting up because they didn't restart. Unless one works at a software development house, I doubt *most* users need their PCs on 24/7.

    Then again, I think I'm being naive for a repetitive intern.
  • Re:The units! (Score:5, Interesting)

    by evanbd ( 210358 ) on Friday December 12, 2008 @12:58PM (#26092145)

    If you need a convenient size, that's what the prefixes are for. A MJ is as conveniently sized as a kWhr. Whr is more convenient in some applications for calculating energy used over time, so it's a reasonable thing to use there.

    Miles per gallon is a silly set of units to use. Metric units would be nice, but have little practical benefit for most usage cases (unless we were to switch to selling liters of gas and marking roads in km, but that's unlikely). The problem is that miles per gallon is backward. It should be gallons per mile (or 100 miles something similar for convenient scale). Why? Distance is the independent variable, not the dependent one. You might want to know how many gallons you'll use on a 200 mile trip, but it's unlikely you want to know how far a trip you can go on with the 8 gallons left in your tank. Furthermore, it's not convenient for comparing operating costs either. You drive your car a certain number of miles per month, not a certain number of gallons. If I want to compare three cars that get 20, 30, and 40 mpg, the cost savings between the first two is bigger than between the last two -- despite the same change in the number. Basically, every time you use mpg, you have to do a division -- not the hallmark of a convenient unit.

  • Re:Winter (Score:5, Interesting)

    by SydShamino ( 547793 ) on Friday December 12, 2008 @02:05PM (#26093177)

    None of that justifies heating with electrical resistive elements. There are two flaws to your argument:

    1. You mix using gas with whole-house heating.

    These shouldn't be mixed. You can have a whole-house gas furnace, or you can have gas units (or a gas fireplace) in critical rooms. Likewise, you can have a whole-house electrical system, or one per room. Or, you could have electronically-controlled baffles for your air distribution, which cost relatively little but allow you to direct airflow to only specific rooms at specific times of day.

    2. You are advocating resistive heating as efficient.

    Resistive heating can be 100% efficient: every watt you purchase becomes a watt of heat in your room (until it leaks out the window).

    But that's not efficient for heating. A heat pump uses the watt of energy you purchased to perform work, moving heat contained in the colder, outdoor air to the warmer, indoor air of your house. The net effect is that each watt you purchase can translate to 3-4 watts of heat in your room. While clearly not accurate syntax, a head-to-head comparison would call such a heat pump 300 to 400 percent efficient, significantly better than the mere 100% your resistive heater generates.

    Then you can use electronic baffle control to direct the heat just to bedrooms at night, and result in an overall system that is quite efficient and doesn't rely on one particular fossil fuel to function.


    My house heats with natural gas, and we have an electric heat pad on our bed for cold nights. In other words, we do exactly the things I advocate against. That doesn't make them right, it just makes my actions wrong.

  • Re:The units! (Score:4, Interesting)

    by compro01 ( 777531 ) on Friday December 12, 2008 @02:33PM (#26093569)

    a Watt-second is a Joule. A Watt-hour is 3600J, and a kilowatt-hour is 3.6MJ.

    Still, *Watt-hours are a more convenient unit, as they can give nice round numbers, unlike what you get using standard time units (who the heck decided hours, minutes, and seconds should be base 60?) and SI units.

  • Re:$75 per year.... (Score:3, Interesting)

    by JoeMerchant ( 803320 ) on Friday December 12, 2008 @03:27PM (#26094313)

    Yep, if your PCs are managed enough that you can get them all to boot up before most people will use them and shut down after most people have gone home - that's a good solution. And, the A/C factor might add a cost factor of 2-3x in the summer (with a somewhat balancing reduction in heating costs in the winter, depending on where you are.)

    Devil's advocate will now raise the (dismissed in the article summary as outdated) concern of heat cycling your chips and any marginal solder joints they may have, as well as starting and stopping your hard drive's spindle and any wear effects on the bearings. I have had many 8-10 year no-failures computers that chug along nicely being run 24-7, they get retired because they are hopelessly out of date. I have also had many computers with significant (motherboard, hard drive) failures after 3-5 years of daily power cycling...

    Many is a word, that only leaves you guessing
    guess about a thing, you really ought to know...

  • Selective power-down (Score:4, Interesting)

    by Todd Knarr ( 15451 ) on Friday December 12, 2008 @04:12PM (#26095029) Homepage

    I've traditionally left my machines running, to avoid thermal stress from power-cycling and mechanical wear on parts from spinning up from a dead stop. I've found the big savings comes from two things:

    • Power down the display when not in use. CRTs were the single biggest power-hog on a computer, and putting them into a low-power standby mode (trickle current to keep the circuitry warm for restart) was an instant 40% power savings. LCDs use less power, but since they don't have coils and beam guns that need to be kept warm I can turn them off pretty much completely.
    • Use an OS that knows how to properly idle the processor and chipset. Done right, you can cut 75% of the mainboard's power consumption without actually powering anything down.

    If I need more power savings, I might spin down the hard drives. But modern drives don't use that much power just to keep the platters spinning, most of their power consumption's driving the heads. Simply retracting the heads and not moving them lowers the drive's power consumption by a fairly big percentage, and that'll happen automatically when the system isn't accessing the disk. None of this requires any fancy sleep or hibernate or suspend magic.

    I have noticed one thing, though. My Linux systems go idle fairly cleanly. Nothing's happening, minimal CPU time gets used (mainly the regular cron process waking up to check whether there's anything to run, then going back to sleep) and the hard drive stays completely idle. Windows, OTOH, keeps pinging the hard drive every 5 seconds or so even when completely idle. It's not much, just enough to make the HDD light flicker, but I don't see that with Linux. It makes me wonder how much of the "You need to put your system to sleep!" hype is simply because Windows doesn't know how to idle properly?

  • by Sigl ( 691196 ) on Friday December 12, 2008 @04:16PM (#26095095)

    I just tested with my 24" LCD. On a white screen it registers 60W. When I change to a black screen (dos window max) it shows 61W.

    On lowest brightness it's 21W. On maximum brightness it's 71W. I originally had it on 80% brightness. When power save kicks in for the monitor it's 0 Watts. This was with a DVI connection. Sorry I didn't check for VGA vs DVI.

    I have a 20" CRT here also. It shows 61W for the maximized dos box and 102W when switched to maximized notepad.

  • by Chezgage ( 630361 ) on Friday December 12, 2008 @04:20PM (#26095149)

    What I'd really like to see is power settings based on the time of day...

    7:55a - wake the PC up, I'm coming into the office
    8a-5p - High performance mode. Display off after 30min. Suspend/Hibernate - never

    5p - Power savings mode. Display off after 10min, Suspend/Hibernate - 30min.

    3a - wake up for downloading updates, virus scan, backup

    4a - back to power savings mode.

    XP and Vista don't have this. Not sure about Linux, OSX.

    Are there any utility apps that can do this?
    Can this be done via network admin?

  • by turbidostato ( 878842 ) on Friday December 12, 2008 @08:08PM (#26098215)

    "What about the extra 5 minutes that it takes me to open up my email, and all the other programs that I was working on the previous day?"

    I don't know you, but my session just opens up all the apps I work on on their desired states; it all takes just a few seconds and no human intervention:
      *Desktop#1: e-mail, opened on the main entry folder
      *Desktop#2: a browser with my "everyday work" sites (like the systems monitoring console and the systems and operations documentation web) and my "morning" sites (like some news sites, Slashdot included), one per tab.
      *Desktop#5: some terminals conecting to some "key" servers I then to log into everyday
      *Desktop#6: another browers with my "administrative" sites (like the timeing and ticketing web app), again, one per tab

    I tried openning the session to yesterday's state but after few days, I found better to start with a clean known state instead.

    Oh, yes: my desktop manager is KDE, which you can use on all unix-like systems, in case yours doesn't allow this kind of customization and you want to give it a try.

Kill Ugly Processor Architectures - Karl Lehenbauer