I still leave my PCs powered on

There’s advice flying around the ‘net today about how much energy we save by shutting PCs off when they’re not in use.

Having widely dispensed the advice to leave PCs on all the time (but I’ve been saying for 15 years to turn monitors off), let me be the contrarian and talk about the counterpoint.The issue is the amount of energy an idle PC wastes doing nothing. And that’s the main reason I’ve always recommended turning monitors off–monitors use a lot of energy and give off a lot of heat, and there’s no particular advantage to leaving them on either. Picture tubes degrade rapidly if they’re left on all the time–this is why every monitor in a used computer store requires you to turn the brightness and contrast all the way up for the display to be readable. Turning the monitor off and on repeatedly isn’t good for it either, but it saves the picture tube.

Now, on to the PC. My PC on its own consumes less electricity than the light bulbs in the room it sits in. Energy costs are going up, but that’s still only a few dollars a year it’s burning. In the 15 years I’ve been leaving computers on all the time, I’ve had a very small number of hardware failures–I’ve lost maybe four hard drives, and one or two power supplies. And I own a lot more computers than the average person. That averages out to one repair every two years on a house full of computers. If I were having to replace a hard drive every year, I’d be spending more money.

Aside from the money, how much energy am I saving by not having to replace lots of parts every year? Isn’t the increased lifespan of my computers worth something?

That’s not the only issue, of course. A computer generates some heat, and in the summer you have to get rid of that heat. But rather than turning PCs off all the time, I prefer to minimize their power consumption. If I don’t need the hottest new 3D video card (which I don’t), then I don’t use it. And the majority of my CPUs are in the gigahertz neighborhood. They do everything I need. So I save energy that way. I get energy savings elsewhere (by using compact flourescent bulbs, for example), so to me, leaving the PCs on makes sense.

In the winter, of course, the heat given off by PCs is a nice benefit. The more heat my computer gives off, the less work my furnace has to do.

I think some common sense is in order. I turn my monitors off when they’re not in use (though LCDs use little power, I recommend shutting them off too in order to conserve the backlight). The PCs I use every day stay powered on. PCs that I only use occasionally–say, once or twice a week–get powered down when I am finished with them for the day. Admittedly I’m more likely to leave a little-used PC powered on in the winter or summer.

If you found this post informative or helpful, please share it!

5 thoughts on “I still leave my PCs powered on

  • October 24, 2005 at 6:43 pm

    Any thoughts about folding-at-home? Since I started running that I’ve just been leaving my desktop machine on all the time.

    • October 25, 2005 at 10:52 am

      Lending your CPU cycles to distributed computing projects like that is a good way for your computer to do something useful while it’s powered on, but its power consumption willl be higher while it’s doing so. Windows NT and Linux idle the CPU when it’s not in use, cutting down on power consumption. It depends on whether you’re more interested in academic research or cutting your electric bill.

      One thing though: Don’t run stuff like this if you’re overclocking your CPU. Projects like this have to filter out results from computers with overclocked CPUs, so adding an overclocked CPU to a project like this actually does more harm than good. Overclocked CPUs are error prone when it comes to basic math. They’re right often enough to not be much of a problem when you’re playing Quake, but it’s a much bigger deal when you’re simulating folding proteins.

  • October 26, 2005 at 3:01 am

    Heck, on the Linux Shuttle at home, I underclock the CPU and memory and there’s not a whole lot of fan activity at all… Maybe I should boost things back up for Winter?

    Related side note: the "Fully Farquhared" Win95b box I built back in 97 for work (P-200 Asus) is likely coming down this week to the immense satisfaction of the IT department (they don’t do retro well <g>). With the exceptions of a few weeks of vacation each year that machine has been running 24×7 since it was built…

    • October 27, 2005 at 9:20 am

      “Fully Farquhared”

      Heh. Now there’s something which needs to make it into the ol’ lexicon 😉

      • October 31, 2005 at 7:29 am

        Hehe, that’s awesome.

        Although, if I were to hear it used I might think it was a bad thing.

        "Hey Rich, is this new desktop Fully Farquared?"


        "You know, Fully Farquared? Best performance, cheap price, enough to do the job, measured twice cut once?"

        "Man, what are you on?!"

Comments are closed.

%d bloggers like this: