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Nowadays with our modern operating systems, is it necessary to fully shutdown computers instead of choosing to stand-by or hibernate computers (desktops and laptops)?

Would there be any side-effects of keeping a computer running continuously without a shutdown (putting it to sleep or hibernating it when it is not used)? For example, hard drive life decrease, system internals (Processors, RAM etc.) aging faster than usual, etc?

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From a software perspective, an operating system and the programs you run on it tend to accumulate all sorts of cruft over extended periods of use - temporary files, disk caches, page files, open file descriptors, pipes, sockets, zombie processes, memory leaks, etc. etc. etc. All that stuff can slow down the computer, but it all goes away when you shut down or restart the system. So shutting down your computer every once in a while - and I do mean actually shutting down, not just hibernating or putting it to sleep - can give it a "fresh start" of sorts and make it seem nice and zippy again.

However, different computers and OS's are not all equally affected by this phenomenon. Generally, a computer with a lot of RAM can go for much longer than a computer with only a little RAM. A server, on which you just start up a few programs and then let them work, will be fine for much longer than a desktop computer, where you're constantly opening and closing different programs and doing different things with them. Plus, server operating systems are optimized for long-term use. It's also been said that Linux and Mac OS tend to run for longer than Windows systems, although in my experience that mostly depends on what programs you use on them, and not so much on any differences between the kernels of the operating systems themselves.

From a hardware perspective, hard drives, because they have moving parts, will age when they are kept powered on. Silicon chips age with heat and power on cycles. Even though the operating system will run without a problem, the hardware will age when left on and when initially powered on.

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I heard bare-bones Windows'95 was rock-stable for months of uptime... especially with no other programs running. –  chronos Aug 23 '10 at 11:22
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@Chronos: That comment may be too subtle for people that never experienced Win95 first-hand. :-) –  hotei Aug 23 '10 at 11:34
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Windows95 famously couldn't run for more than 49days because of a wrap around in a timer - but nobody ever discovered this! –  Martin Beckett Aug 24 '10 at 1:43
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95 && 98. Download the patch and keep on kicking: support.microsoft.com/kb/216641 :) –  John T Aug 24 '10 at 2:25
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@JFW - I think it was more a case of no win95 machine stayed up for 49 days because of other problems, or the fact that MS required you to reboot everytime you changed anything. –  Martin Beckett Aug 24 '10 at 15:07
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This question comes up a lot. My take on it is "it doesn't matter". Shut it down if you feel compelled. Leave it on if you want to. Personally I use suspend a lot.

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Yes, suspend is a synonym for hibernate. –  Torben Gundtofte-Bruun Aug 23 '10 at 7:39
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Depends on the system. On XP, for instance, suspend saves all the state to RAM, and leaves the computer powered on at a very low power. When you leave suspend mode, the cpu state is copied from the RAM. Hibernate, on the other hand, saves the contents of the memory to disk and actually powers down the system so that you can even unplug it. When you turn it back on, instead of booting the OS, it restores it from the disk. –  Nathan Fellman Aug 23 '10 at 8:08
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Yes, of course-Different OS has different terminology for basically the same actions. For Mac, stand-by is sleep, while hibernate is deep-sleep. –  JFW Aug 23 '10 at 11:18
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@torbengb: On Ubuntu (Linux) they're different. Suspend -> RAM. Hibernate -> Disk. Suspend recovers almost instantly which I why I prefer it most of the time. +1 to Nathans explanation why. –  hotei Aug 23 '10 at 11:36
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It depends. In general, you don't need to. You're likely to replace the system before you reach the lifespan of the components.

However, there are a few differences between the modes that can be important. Power-on and often suspend (power-on suspend, with small voltages keeping the RAM fresh) both still draw power from the PSU and the wall. In a thunder storm, hibernate (power-off suspend, with RAM saved to disk) or power-off offer more protection from shocks (and you can unplug the system).

In addition, power supplies tend to have the shortest lifespan of any part of a system, besides maybe fans. Guess what two of the parts that usually stay on when you suspend your system are?

Now, your power-management settings do change the question a lot. If you have it set to a very low-power mode, then it becomes less of an issue. Higher power modes, or keeping the screen or drives on, and it's a better idea to shut it off.

Is it necessary? No. Is it a good idea sometimes? Yeah.

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Indications tend to be the computer not starting, or starting and shutting down half a second later. The PSU converts wall power to computer-friendly current and voltages, so it's pretty important. Luckily, it's also pretty easy to replace. As far as affecting other parts, it can if it catastrophically fails. I had one spontaneously blow out complete with sparks and smoke, and while it was quite the light show, it burned out the motherboard, processor and 3 of the 4 sticks of RAM in the process. That's not too common, usually they die quietly and your system just won't start. –  ssube Aug 23 '10 at 4:57
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I have had numerous (> 10) power supplies fail over the years and I've never lost anything but the PSU in the process. The quality of the PSU is important. I replace OEM PSUs with Antec now and have had 0 failures in last 10 years or so. Your mileage may vary. –  hotei Aug 23 '10 at 11:29
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@hotei Ouch, over 10 failures? I hope you work with lots of machines! @JFW I've had a PSU blow on my home desktop a long time ago, which took out several components - my own fault, it was fairly cheap and I think I overloaded it - and I've since been told (not verified!) that a buzzing sound from a PSU (especially if the PC is off) is a sign that the PSU if on it's way out - can anyone confirm he accuracy of this? –  DMA57361 Aug 23 '10 at 11:50
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@DMA57361: That's 10 fails over 30 years and maybe 50 or 60 different machines. I also started using UPS on everything and that probably helped as well. It was cheaper to overbuild with PSU and UPS than to chance the loss of our business data. PS: A continual (non-fan) buzzing is the sound of impending doom. Failure is right around the corner - usually accompanied by an acrid odor from PSU. –  hotei Aug 23 '10 at 14:11
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@JFW - I haven't bought many (clearly no where near as many as hotei!) to be confident in giving a recommendation, but both Antec and Corsair are both reputable. And, @hotei, thanks for confirming that electrical buzz from a PSU is a serious warning. –  DMA57361 Aug 23 '10 at 14:25
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The most obvious effect of leaving a computer running rather than shutting down can be seen in the electric bill. A computer will still draw power while in sleep mode (significantly less than when running), but if it's in hibernate mode it won't draw any more power than when it's off.

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+1 I switch my desktop off when not in use (for longer periods, such as overnight or if I'm going to work/shop/etc) and then switch of the surge protector it, and all the peripherals, are connected to. It doesn't even drain the (admittedly tiny) power it would when off this way (neither do the screen, speakers, printer, etc). –  DMA57361 Aug 23 '10 at 8:15
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Me, too. For people, who don't switch off unused computers or TVs, energy obviously is (still) too cheap. –  Mike L. Aug 23 '10 at 9:01
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Well a computer in stanby (sleep) will only use 10% of it's power-on fully idle consumption. Hibernate is the same as shutdown, where only a few components receive minuscule amounts of power (usually motherboard, maybe NIC). The difference between sleep and powered-on is massive yet the wake time is only a few seconds, so always put the computer into sleep when not using it. –  Mircea Chirea Aug 23 '10 at 10:08
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@iconiK It might be minuscule drain, but if I disconnect 10-15 objects accross my home it's quite a bit over a year, and it's not just mobo & NIC when "off", there's your screen and anything with an external power-pack draining as well. Also, do you really need your computer to switch on and be ready within 5s? I tend to switch mine on, go and make a cuppa, and then it's ready to use when I get back to my desk. –  DMA57361 Aug 23 '10 at 10:40
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@iconiK But you only need to boot the machine once per work day. And, the first 2minutes from an 8hour work day is hardly much of a waste (incidentally "several minutes" to boot up is appauling slow). Over the course of a working day I'm away from my desk much longer than 2mins from just a few loo breaks and to get a few cups of tea. And lets not compare it to the time people can waste on SO or SU! ;) –  DMA57361 Aug 23 '10 at 11:09
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All components like HDD, DVD-ROM's have a rated MTTF defined i.e number of spinning hours before failure, make sure you check the ratings for accurate figures. Most laptop HDD's used have thousands of spin down cycles before they die down.

As with all mechanical devices, more number of power down cycles causes more wear and tear than keeping it actually running all the time.

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Your last paragraph: do you also keep your car running? –  Mike L. Aug 23 '10 at 9:00
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@panzerschreck: Under many situations power management causes hard disks to park heads or spin down completely when the PC is on but idle. This itself causes wear eventually. –  James Aug 23 '10 at 9:59
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this is why you set power management to not do that. –  Sirex Aug 23 '10 at 10:28
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and then instead of power cycle's causing problems you have constant mechanical wear causing problems. So, the real question is - which is more likely to cause breakdown? Do we have any stats or research on this? –  DMA57361 Aug 23 '10 at 10:46
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It should be noted that the disk parks the read/write head partly to protect against shocks so it is normally a good thing and more common on laptop drives. –  James Aug 23 '10 at 12:28
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Other than the energy uses mentioned, further disadvantages of running your computer continously (i.e. not on standby) when not using are:

  • Fans get clogged up with more dust which can eventually cause overheating
  • More risk of power cuts/surges that can potentially do damage (mainly to desktops). This might still be a problem if it is on standby though.
  • Computer may be more vulnerable to remote attacks if you happen to have unpatched/susceptible software and an inadequate firewall. Of course you want to make sure that your computer does not have this problem regardless of how much you use it.

Advantages:

  • Less heat up/cool down cycles that eventually damage certain components
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Would using a PSU in the build stop the power cut/surge problems? What would happen to the desktop if the electricity cuts/surges? Damages to the filesystem/HD or also other interior parts too? –  JFW Aug 23 '10 at 11:21
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RE you're first sentence: You have to use a PSU (Power Supply Unit) in a desktop, it's not optional - it's what steps down the mains voltage for your components, are you maybe thinking of UPS (Uninteruptable Power Supply)? In a power surge most(all?) PSU's will not help much - if they cannot absorb the extra voltage they may blow, pass the surge on to your components or possibly both. And power cuts are less of a concern now compared to the past (and a PSU won't help here) - but you can still loose data and/or corrupt files (but it's much less common than in "the old days"). –  DMA57361 Aug 23 '10 at 12:05
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A UPS is designed to handle power cuts - it provides a backup battery for a short period (sometimes only minutes) to allow the desktop to be shutdown correctly. Some UPSs will automatically send a signal to an attached PC and give a shutdown order when the battery is low (much like a laptop does). Most UPSs should also help with surges, sags and spikes - but check what a device covers before purchase. –  DMA57361 Aug 23 '10 at 12:29
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I have a MacBook that's about 3 years old now. I probably do everything 'wrong' but, it has not failed me yet. I wanted to share my experience with my habits. I rarely shut down. I will always shut down or at least unplug (if I'm working) during a thunderstorm. I use sleep mode. My laptop is plugged in the majority of the time. During these last 3 years, I have not yet experienced any system slowness, decreased battery capability or any other problems. I know that some people experience adverse effects when doing what I do but, it's worked for me. I am also "one of those people" that plugs their smartphone up to recharge every night whether it needs it or not. Still, no ill effects there either.

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I use hibernate if I'm going away from my computer for an extended period of time (instead of shutdown). I use sleep mode if I'm just leaving it for a little bit (to save some power instead of just letting it run).

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No slowdowns. I'm a fairly heavy user, using lots of resource intensive apps, and don't have any issues like that. XP and Vista SP1 just don't have that issue. Other than non-SP Vista, I haven't seen slowdowns due to time "up" since Windows ME. It just doesn't happen anymore. –  Brian Knoblauch Aug 25 '10 at 11:39
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No one can really give you an answer to this one (It would be like predicting the future, no?) so all one can give is his own experience, which in my case would be this.

The machine I'm writing this on is a laptop - the last time it was reset/shutdown was 16.7.2010. (a little more than a month - guess I installed something that needed a restart back then); otherwise from that occasional restart it has been running for about two years now on a wooden table (big wooden table :), no special cooling or anything. A few times a month I put it in standby, or hibernation (more often standby), but that doesn't exceed more than, I don't know, few (5 ?) days a month.

Other times it usually stays on, doing its stuff.

Maybe one day it will die, no one can tell. So far it's been working just fine.

Generally, I've been using this approach from the late 80' ties - components in general die very rarely on me.

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There are about a hundred different ways to answer this question and so far everyone is telling you the same thing. It really doesn't matter anymore - there are a lot of people out there that still believe this old wives' tale (you must shut down at end of the day). Whatever. I have a client with a server that has been in continuous operation since the day I installed it 6 1/2 years ago without ever shutting down except for maintenance & updates. I shut down my PCs at home just to save electricity because I'm a cheapass and I am saving the planet. With today's advancements in technology it is not necessary to shut down / power down / sleep / or anything else. It is a matter of taste now.

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I honestly think there isnt, i put mine in sleep mode and even when the power flashes it just wakes up, it is great for me because i can just sit down hit my space bar look something up and put it back in sleep mode. now it may not be the safest option on your harddrives and power surges.

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I have a computer that has been running since 2001. It controls my Dodge Neon.

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This is a very old question ... debated over and over and over. The real answer always tends to be "depends on what you are planning on doing" ... if you have no need to keep the PC on then use one of the power-saver modes: sleep, hibernate, suspend or shut down. If you plan remote access, wake on LAN, etc then you need a less green approach ... modified sleep or left on (with settings for shutting off display, drives, etc set according ot your needs).

Most modern operating systems have facilities for cleaning RAM, swap files, etc ... but David Zaslavsky's response is spot-on ... performance will definitely get a boost by a complete shutdown on a regular basis. Even the best-written software can have memory leaks, lost pointers, etc. Also, many graphics cards share core memory ... and those are far less adept at keeping their memory kernels clean and tidy!

Although pretty robust these days, the hardest function of a hard drive is starting up and shutting down ... so be careful with those sleep and hybernate settings ... they can repeatedly wake up the hard drive(s) if your not careful.

Personnaly, I shut my computers down ... all the way. No need to keep the juice flowing when I'm not home ... and, using Windows 7, the PCs start up in a flash.

I have a feeling your question will never be definitively answered ... the chicken-or-the-egg quandry of the PC world!

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I don't want to shutdown, but thing is I use ubuntu, and If I wont shutdown it properly , it will be messed up , as it was installed on top of NTFS

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This is a little different take on your question: I'm looking more at the "Should I shut down properly vs can I just cut the power?" question:

I can't find the reference now, but I remember reading an article back in 2003 about a large company where the IT department had done an internal study: they took two very similar departments and taught one of them to always carefully shut down the PC when the left of the day for security reasons. This was strictly enforced. The other department was instructed to leave them running under the ruse that IT wanted to be able to connect remotely for maintenance. Again, this was strictly enforced, and they would then kill the power to the machines each night. This went on for a year, and support costs for each department were tracked.

The result of the study was there was no measurable difference in support costs for the two departments between those that shut down the computers correctly, those that just powered them off without shutting down, or either department compared to the year prior.

But what does that really mean? I know there's at least one problem with the methodology — there should have been a third department tracked that was allowed to do as it pleased for a control, and perhaps another department where machines were kept running as much as possible.

We also need to be careful not to draw the conclusion that this means it won't ever cause a problem with your machine; it's very possible that powering off the computers without shutting down did break a few machines in the study, but this either did not measure statistically for the support costs (maybe it's more likely to happen near the end of a PC's replacement cycle, for example, which reduces perceived cost) or is offset over many PCs by something like wear incurred while shutting down properly. Also, PCs from 2001-2002 and prior (when the study would have been conducted) are different from those built today.


As for the question as asked: I usually leave my work desktop turned on. I like being able to pick up in the morning right where I left off the night before. I do something similar with my home desktop. My laptop, though, I try to remember to shut down much more often. Additionally, I like to make sure I shut down when leaving the office for the weekend on Fridays.

For the servers I manage where I work (about 13, hoping to consolidate to 6 via VMs in the next year, 3 or 4 the year after), I have a maintenance cycle scheduled every month where I can restart them if I want. Most months every server is re-started, but sometimes I'll decide not to interrupt them. My maintenance cycle comes over the weekend on first weekend following Microsoft's monthly Patch Tuesday.

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It really depends on preference. The facts are simple. Leaving a computer running will put more usage hours on the hardware, which will shorten the hardware's lifespan. Leaving the computer running also generates heat and uses electricity. Are there cases when leaving a computer running is ok? Of course! Many people use the time they are away from their computer to schedule resource-intensive tasks like A/V scans and media transcodes. Personally, I change my habits based on need. Most of the time, my machine runs 24/7 with reboots as needed for security updates. During the hottest part of summer (I live in AZ), I turn it off when I go to work unless I have a workload that needs done. Software-wise you can easily leave a system running for weeks or months without any noteable issues. In the end, it comes down to what you want :)

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If your machine is encrypted, there are hacks / tools which can extract keys from memory (if you have suspended they get put back into RAM when the machine is fired up).

These can then be used to decrypt a copy of your drive. Done right, this is all done offline and you may not even be aware (if you have left your machine unattended, eg overnight while the cleaning crew are in.

Shutting down an encrypted machine is the surefire way to prevent such attacks.

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At work we leave our computers on Mon-Fri, sometimes Saturday. Our servers push updates in the evenings so they need to be running.

My home PC, I can leave it on for about a month, then MS wants to reboot because of software updates. I try to limit doing them to once per month unless there's a desperate need to update right away for security reasons.

As for linux servers hosting web sites, I've had one go for 300 days and it still performed well.

In all cases, having a lot of memory helps keep it going longer. CCleaner will help clear some stuff out while the machine is still running. You can also manually close processes down yourself.

If you watch your memory usage, you'll notice when you open and close an app, not all your memory returns. Some is cleared. Some is left as cache. And some just seems that the program still retains until reboot. There's third party tools to help clear this out.

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