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Is it better to leave your computer on all the time?

I tend to leave my PC on all the time, unless I know that I'll not need it for at least a few days (i.e. holidays). I do this because I believe it's better for the components to have them 'warm' all the time rather than 'shocking' them once a day with a switch on from cold. But now, with energy consumption in the headlines, I'm starting to feel somewhat guilty. What's the majority opinion? Should I leave my PC on all the time?

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migrated from stackoverflow.com Nov 2 '09 at 7:07

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marked as duplicate by Arjan, joe, Diago Nov 2 '09 at 19:41

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It'll be way past obsolete before thermal cycling becomes an issue. Might as well just save the electricity. –  Brian Knoblauch Nov 21 '08 at 20:01
Hmm, this is an old question, just now migrated from SO. However, here on SU it is duplicate of superuser.com/questions/2733/… –  Jonik Nov 2 '09 at 9:23
Odd, there's more of those old questions coming in. Not sure I like that, but the answers might have some value here. It took me some time to decide if I wanted to vote to have this older question closed. But well, it should never have been asked at Stack Overflow, so yes, I guess closing should not make the original questioner feel bad... –  Arjan Nov 2 '09 at 10:13

12 Answers 12

From the "Rocky Mountain Home Energy Brief"...

Arguments that thermal cycling harms the internal components of computers don’t seem to be well founded. Modern computers are designed to handle 40,000 on-off cycles before failure, and you’re not likely to approach that number during the average computer’s five- to seven-year life span. In fact, IBM and Hewlett Packard encourage their own employees to turn off idle computers, and some studies indicate it would require on-off cycling every five minutes to harm a hard drive.

Now, this quote is taken from a study done in '95, so how the numbers may have swayed in one direction or another. But I do imagine 'sleep' modes to be sufficient for daily uses. A hardware designer once told me that sleep is good for the work week, but if your computer is out of use for more than 24 hours, it's actually bad for the components to keep them in that constant state of readiness. In other words, more than 24 hours, shut it off.

On another note, any electricity use, as it stands now, necessitates the burning of coal. This is a bad thing. So until we move to renewables like solar, wind and hydro, electricity use should be a concern no matter the use. Remember, its not just our use, but our combined use that's the problem.

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"necessitates the burning of coal"? What about nuclear and hydro-power areas? –  warren Nov 2 '09 at 11:41

I shut mine off whenever I can. Every little bit helps and each of us contributing our own little bit to a greater good can hardly be a bad thing.

I'm religious about shutting my PC off at work and at home. The best way to change tomorrow is to start today.

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These days computers are getting incredibly efficient. The laptop I'm typing this on uses less energy on average than a single energy-saver bulb.

If you're really worried, turn off your monitor or something thats non-critical.

Our poor little home desktops are only 1% of the problem in the 1% of the problem which is computer based power-wastage.

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?? What laptop are you typing it on? –  Josh Comley Nov 2 '09 at 9:35
yah - I've never seen one that draws only ~17 watts! –  warren Nov 2 '09 at 11:42

I close the lid of my notebook and turn off the external monitors when I am leaving it for more than 30 minutes. I would like to hope that we all feel a collective responsibility to eliminate power waste.

When I lived in Japan I used to have these little plug 'adapters' that had a little display showing the electricity usage and cost. They were VERY cool, I wish I could find something like that here, as it would be nice to see how much electricity usage various devices actually use. Anyone seen this in North America?

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Do a search on Kill-A-Watt. ThinkGeek and SparkFun both have them. –  Philip T. Nov 21 '08 at 21:30
beautiful - thanks. I just ordered one to try it out. I like the power bar idea. Might get a few of these as gifts this year... –  aSkywalker Nov 21 '08 at 21:53

Our company is nearly ready to enforce a company-wide automatic shutoff of computers after a given amount of idle time. Power savings are actually a secondary benefit for us - the primary benefit is that security updates get pushed when the computer is turned back on.

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The bigger issue is energy consumption. This calculator shows you that even an "energy-star" PC might cost $100/year just to keep on 24/7. It will also heat your house a little, so that might be mitigated in the winter. If you do leave it on, at least turn off the monitor.

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At work I usually only shut my computer off before the weekend. At home it depends on the season. Since running my desktop noticeably raises the temperature in my room, I always shut it off during the summer. In the winter, sometimes I'll leave it on if there's a long-running job I want to run. So you might say my computer keeps me warm at night. :( But only in the most literal sense

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It depends a lot on a computer. I estimate the idle consumption of the workstation I am typing this on (Intel Quad Core 2.4 GHz, 4 GB RAM, ATI X1950, Asus board) to be something like 100-200 W, which is significant - and I am always turning it off when I think I am leaving it for hour or more. On the other hand, if you are using some low power computer, like a laptop, it will probably be much better.

In our company we even have a policy to turn off your computer when your are leaving at the end of the day, unless you have some reason not to do so (like running some job there) - the electricity bills for 50 computers running idle at 100-200 W each can be surprisingly high.

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Part of this depends on from what setting you are looking at this:

1) Corporate/Enterprise use. In this case, there is a policy where I work to leave the machines on all the time as there may be times when IS administrators may need to do some work and thus need the machine on to do that.

2) Home use. In this case, if you are part of the Worldwide community grid or folding@home project then there is a reason for your PC staying on all the time.

I would suggest powering down the monitor when not in use as the older CRTs could get a little toasty inside though I'm not sure how bad an LCD would be in this case.

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I don't because mine is a server. If it's every off, something has gone wrong (and i'll be completely flustered).

I calculated my overall energy consumption and, for the past few years, have purchased renewable energy credits every month to help me feel better about my energy use.

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Consider turning off the monitor to save the backlight bulb and turn off the hard disk to save the bearings.

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Almost always, unless I know I'll be re-using it very soon, in which case I'll send it to sleep. I even turn off the UPS (which shuts down the router, cable modem and a couple of other "always on" gizmos.) I've been doing this for years and never had any sort of hardware problem. My current PC is 2.5 years old, the one before that was almost 5 years old when I replaced it, and never had any problems. I'm not obsessed enough with boot/startup times to waste electricity. I often hear "oh but it only costs so and so", and then those same people bitch when they get their power bill (...) All those "but it only costs..." add up to real money in the end.

Power surges are a much greater threat to your system than turning it off. My last PC was killed by a power surge when they replaced the power meters with "smart meters". In fact that surge was so bad, it blew up a few other electronic components in the house. Oh and, they were all on surge protectors...

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