Better to turn off or leave on?

[dorpis]

Someone told me it's best to leave a computer on, since turning it on uses alot of energy. I'm a bit confused about it. And if I have a computer alarm, will it work if I leave the comp on stand by?

[Odd_Nonposter]

From what I understand, turning it off at night and back on in the morning saves more energy than leaving it running all night. But, if it's only going to be an hour or two, the benefit of not having to restart outweighs any sort of energy savings. You can turn the monitor off if you're going to leave it for half an hour, though.

[Taosaur]

FWIW, I've tried it a few different ways, from leaving everything on all the time, to plugging the PC and all peripherals into one surge protector, shutting down and then hitting the kill switch on the surge protector, to what I do now: shut down the PC and turn off the monitor at night, leaving the modem and router running. My electric bill did seem a few dollars higher when the PC was running all the time, but I see no difference between cutting power to everything and simply turning off the monitor and PC.

[ninja9578]

Consider this: Leaving a laptop on overnight will drain your battery to nothing, booting it up doesn't make a dent. Booting a computer up doesn't take any more power than running it for the 10 seconds it takes to boot. Anyone who says otherwise doesn't understand Newton's Laws. Turning it off ALWAYS uses less energy than leaving it on, even the most superefficient laptops.

[Replicon]

Also, if it's a desktop rather than a laptop, you definitely want to turn it off, especially in the summer. I actually saw a MAJORLY noticeable difference in my electric bill just from having turned it off in the summer (it was like almost cut in half). Running one of those beasts day in, day out, when you only use it maybe 2 hours a day or whatever, is insanely wasteful.

[khh]

Consider this: Leaving a laptop on overnight will drain your battery to nothing, booting it up doesn't make a dent. Booting a computer up doesn't take any more power than running it for the 10 seconds it takes to boot. Anyone who says otherwise doesn't understand Newton's Laws. Well, your hard drive works less during idle time than when you boot, and possibly your CPU too. However, the difference is probably less than 10 seconds runtime. Probably less than 1 second too.

[Ynot]

If you have your computer's power management setup correctly, you can eliminate a lot of waste - Cut power to the screen - Reduce HDD spin speed - Reduce fan spin speeds (more of a noise thing, than power) - Reduce CPU frequency (Eg. Intel's SpeedStep - AMD have something similar, but I forget the name) - Reduce GPU frequency (Eg. nVidia's PowerMizer - again other manufacturers have similar things) I'm probably missing a few things but, if you need your machine on 24/7 (serving other machines / bulk downloads / etc. etc.) there's plenty to be done to reduce power usage

[khh]

Oh, and about the alarm: If it's set in BIOS, it should work even if you turn off your computer, provided you turned it off normally and the power was never cut. If it's supported, you can set up your computer with Wake-on-Lan (WoL), which allows you to boot it up remotely by sending a package from another devise (computer, smart phone), the same restrictions apply.

[Marvo]

Consider this: Leaving a laptop on overnight will drain your battery to nothing, booting it up doesn't make a dent. Booting a computer up doesn't take any more power than running it for the 10 seconds it takes to boot. Anyone who says otherwise doesn't understand Newton's Laws. Turning it off ALWAYS uses less energy than leaving it on, even the most superefficient laptops. My computer produces energy when it's running!

[Keresztanya]

If you have your computer's power management setup correctly, you can eliminate a lot of waste - Cut power to the screen - Reduce HDD spin speed - Reduce fan spin speeds (more of a noise thing, than power) - Reduce CPU frequency (Eg. Intel's SpeedStep - AMD have something similar, but I forget the name) - Reduce GPU frequency (Eg. nVidia's PowerMizer - again other manufacturers have similar things) I'm probably missing a few things but, if you need your machine on 24/7 (serving other machines / bulk downloads / etc. etc.) there's plenty to be done to reduce power usage AMD's feature is called Cool'n'Quiet, I believe.