Helping people with computers... one answer at a time.

Depending on your usage, turning your computer off at night might be appropriate. But is it actually saving energy? In the long run, it's hard to say.

A friend of mine told me it is better to not turn off my desktop computer every night, instead to turn it off every few nights and just put it on standby every night. I work from home and I use my computer religiously. Is it really better to not turn it off every night? I have a 4-year old dell Desktop (Dimension 2350) with one of those old clunky monitors. Is putting it on stand-by saving as much power as turning it off? Also, does turning the computer on and off affect it negatively?

This is one of those areas where there's some significant difference of opinion. Not "PC versus Mac" differences, but nonetheless.

Depending on who you ask, the answer is yes, or no.

My answer, naturally, is "it depends".

The issue isn't quite as clear as one might think. There are two issues at play here: power usage, and for lack of a better term, "stress" on individual pieces of hardware.

Power's actually the easier one.

In most cases Standby is "almost as good as" turning your computer off. Standby typically uses a little power to keep certain components ready to be used, but components that use a the majority of the power are actually turned off when the computer is placed on standby.

That being said, I almost never use standby - however my reasons have nothing to do with power saving or device wear and tear.

The only thing standby really does for you when it works it to save the state of your machine so that when you power on you don't have to go through the entire boot and application start sequence. Personally, that's only important to me if I'm using my laptop and want to preserve the battery life during the day without repeatedly rebooting.

In addition, I also seem to periodically experience problems with device drivers that don't resume from standby properly. This has definitely improved over time, but I still get bit occasionally. Particularly for overnight scenarios, if I'm going to turn the computer off, I'll actually turn it off and let it do a "real" reboot when I turn it on in the morning.

But if standby works reliably for you, then I'm happy to consider is "close enough" to a complete power off for purposes of power use.

One last item to throw in to, and perhaps further confuse, the power issue is that your computer may already be taking steps on its own to minimize power usage when you're not using it. "Energy Star" compliant monitors, for example, will effectively go into the equivalent of standby all on their own if you don't use your computer for some period of time. Some computers will automatically turn off hard drives after some period of inactivity as well. So it's quite possible that, depending on your computer, simply by walking away from it you'll reduce the amount of power it's using. It's not as great a reduction as explicitly selecting standby, or turning the computer off, of course, but it's a step.

Now, let's talk about hardware and stress.

There is an argument that says leaving a component on continuously is less stressful on the component than turning it on and off repeatedly. While saving power, that stress contributes to earlier failure and required replacement. The argument goes that the eventual cost of replacing a broken device is so high (in terms of both purchase price and environmental impact) that in the long run it would have been more cost effective to simply leave it on all the time.

"Excessive heat is more of a danger than the number of times you turn the computer off and on."

The counter argument is that most components today are built with this in mind. Indeed, as I mentioned earlier many components will turn themselves "off" after some period of inactivity whether you tell them too or not. The devices are, themselves, built for, and choosing to, power cycle fairly frequently.

And in almost all cases, the devices are lasting longer than we need them. By that I mean in most cases devices are replaced not because they broke, but because newer and more powerful devices have been purchased.

As you can see, the answer is much less clear on whether, and how often, one can safely turn off the power to your computer.

One thing I will add that isn't technically part of this question, but impacts your computer's lifespan more than power cycling is ventilation. Make sure that your computer has good airflow through and around it, and make sure that dust doesn't accumulate on or in it. Excessive heat is more of a danger than the number of times you turn the computer off and on.

The bottom line.

Confused yet? It wouldn't surprise me. The problem is that there's no real clear answer.

My expectation is that a "normal" user who uses their computer perhaps for a few hours a day would most likely turn it off, or put it into standby, when it's not going to be used for a few hours or more. And that's simply to minimize power use. It's also not a big deal if they don't.

Personally, I make the decision based on how I use my computers. That means that all of my computers are on 24 hours a day. But as you might expect, I use several computers heavily for long periods of each day. And more importantly, over night they all execute critical back-up and synchronization tasks that I rely on.

Article C2968 - March 20, 2007 « »

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Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

March 20, 2007 12:54 PM

There's also "hibernate mode". This saves the state of the computer (as does "standby"), but it saves it to the hard drive, and actually does power off. Powering on then restores the state from the hard drive, rather than doing a "full" boot.

Of course, the answer to "which way to go" is "it depends". I happen to leave my desktop on most nights, but I do power down to hibernate other nights. (No particular pattern as to which one.)

My laptop, however, I almost always hibernate overnight. (Or longer sometimes.)

However, I have numerous programs running, and windows just where I like them, so I like the fact that they're where I left them with hibernate.

March 23, 2007 7:52 PM

You never mentioned anything about how not rebooting the machine properly at least once every few days, software related problems start occurring such as 'junk' building up and the OS being more likely to corrupt itself.

As for a further question, can I computer become infected by being connected to the internet during standby?

Leo Notenboom
March 23, 2007 8:08 PM

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Nope, with your machine in standby your network connection is inactive.

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deyaa fahmy
March 23, 2007 10:17 PM

My computer is always On since 3 years at least, except about 15 days per years my holiday.

March 24, 2007 1:14 PM

I've been leaving my machines on 24/7 for years. This is due largely to my own impatience and a degree of laziness rather than for any technical reason: I hate to wait for it to boot up! That said, I've never experienced a problem related to or as a result of leaving them on. So, as Leo the wise has indicated, it is largely a matter of personal preference. I would recommend keeping the machine clean (clear cache, etc.) and an occasional reboot. My machines seem happier when I do this than not.

November 9, 2007 6:53 PM

If I leave my computer on for long periods of time, it seems to "load up" on me. Everything slows down, things sometimes quit working. I have a Dell E521 with Vista on it (bought new this past summer). In fact I use yahoo messenger and it freezes up on me all the time. It gets better when I shut the machine off and restart it. But I always shut mine off at night, as I've already had 3 fans burn out on my old computers.

March 7, 2008 6:37 AM

why is it bad to turn off the computer and why do you have to reset the date each day

Leo A. Notenboom
March 9, 2008 9:16 PM

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It's not neccessarily bad to turn off the computer. (Read
the article you just commented on.)

You shouldn't have to reset the clock every day. You
probably have a dead CMOS battery. That can be replaced.


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June 4, 2008 5:18 PM

i am definitely more educated on this matter now that i have read your answer to this question. Thanks for the info Leo

Elaine Gonzales
August 12, 2008 1:35 PM

My Gateway computer is 7 years old, it has windows XP , lately it has started to put itself in standby when I am using it and I can't bring it out. I have to turn off all power and wait a long time before it will come up again then, it closes itself down again.

October 15, 2008 2:11 PM

Hi Elaine Gonzales,

You might want to check your power settings to ensure that it is not set to go into stanby mode ever so many minutes.

February 5, 2009 8:42 AM

Hi Leo,
When I return to work in the mornings, my computer does not boot up unless I manually turn it off, then turn it back on. I don't shut down my computer when I leave in the evenings. Normally, it hibernates, and I come in and press the space bar, and its back up. Now however, the blue light is on, and when I press the space bar, I can hear the computer "roar".. but nothing comes up on my monitor unless I turn it off, and then turn it back on.... What should I do??

February 21, 2009 4:11 PM

please can you tell me how to turn off power safe mode on my computer.i try boothing my computer and all i see is a black screen telling me my power safe mode is on.

February 21, 2009 4:19 PM

what should i do?i was using a friend's computer when all of a suddenly it went off without any warning.i was able to reboot the computer but everything on the desktop as become faint which makes difficult reading or seeing on the desktop.what can i do.really need help.

October 24, 2009 11:00 PM

Surely you should turn off your modem when not in use to prevent high tech hackers from getting in the back door. Our local police claim they can access info about you while you are turned on.
A Microsoft engineer friend of mine had a message left on his screen while he was absent telling him that he needs to purchase better protection. Would be interested in you comments, Leo. Thanks

My computers are on 24x7. The more important thing is to have a good firewall, which will prevent exactly the type of access you describe. It can be a simple as a NAT router.

June 6, 2010 9:40 AM

An important factor is the price of electricity in your location. In the Netherlands we pay an additional environment tax of about 250% and then 19% sales tax on top of that. Together with meter rent and electricity transport costs that brings the total to about 25 Euro-cents per kWh.

August 22, 2010 5:21 AM

Most of the updates require your system to restart after instolation and as you have mentioned earlier they are could be as frequent as few per day. So the wear and tear factor is unavoidable in that perspective however I belive restarting is beneficial for the system anyway am I confused or it is?

It varies a great deal on how you use your computer. I have my main machines reboot overnight. There's really no additional wear and tear to doing so.

October 15, 2011 11:03 PM

powering down the computer stress critical components such as the CPU and memory.. so does this practice is more waste?
-thank you-

That's actually discussed in the article you just commented on.
November 11, 2011 5:39 AM

As Leo says, it depends. It depends on a myriad of things.....things as basic/minuscule as "what is my time worth", assuming you have to, perhaps, walk to another floor of the house to turn off your server......or, "how many people in the family use the network...and at what times of day". It definitely can't be a one-size-fits-all answer.

John H
December 14, 2011 8:36 AM

Your article was very helpful but my problem is that My Dell Dimension E510 has just developed early stages of the dreaded flashing amber light on startup which effects powering up. At the moment I get away with massaging the start button for about 5mins but for how long!
It starts up OK from standby so my dilema is will I be causing less stress by leaving permanently on standby or risk complete failure by stwithing off every night if and when my existing fault develops further?
John H

June 24, 2012 8:34 AM

Hi Leo, I live in an area that is prone to thunderstorms. I had to have the power supply
replaced due to lightning striking the power line.
It was under warranty. Now I log off and shutdown when I quit. I have a UPS; and it helps
when there is a power failure.

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