Technology Explained

Pros and Cons of Leaving Your Computer Turned On All the Time

Andy Betts 14-07-2015

It has been one of the most long-running discussions in computing: is it better to leave your PC turned on when you’re not using it, or should you always turn it off?


There are actually some pretty solid arguments for either approach, meaning the answer depends on how, and how much, you use the computer. Let’s take a look at some of the pros and cons.

Why You Should Leave Your Computer on All the Time

There are several good reasons why you should always leave your computer on. It’s not just about being quicker to get started, but it can enhance the functionality of your PC too.

It’s More Convenient

The main reason why you’d want to leave your computer on is for convenience. Rather than having to wait for it to boot, it’s always ready to go.

A typical system will take around 30 seconds to a minute to boot into the operating system — depending on the specifications, of course. If you have a large number of programs that are set to launch on boot it’ll be another minute or two before you can actually get to work.



Leaving the computer on bypasses this problem. Awakening your PC from Sleep mode Sleep Mode vs. Hibernate Mode: Which Power-Saving Mode Should You Use? What exactly does Sleep mode do? How is it different from Hibernate mode, which is an extra option on Windows computers? Which should you choose, and are there downsides to using them? Read More will take just a few seconds, and all your previously launched apps will also still be running.

That said, the benefits are dependent on your computer’s hardware. A PC with a solid state drive will have a significantly shorter boot time 6 Tips for Rebooting Windows Like a Pro Windows' strength is customization and it doesn't stop at shutting down. You can end your session or reboot your system in various ways, many offering more convenience and control than the Start menu. Read More than an equivalent machine with a traditional hard drive. Depending on how your machine is configured, you may decide that booting is no great inconvenience.

Your Computer Will Stay up to Date

There are numerous tasks that are essential to maintaining your computer and data. Almost all of them are better off being performed overnight.

time machine


Installing operating system updates, creating backups, running virus scans, or uploading large amounts of data such as moving your music or photo collection to the cloud Online Photo Albums: Where to Host Them for Free Which online photo storage service is the best? Between free price tags, unlimited storage space, and photo security, which service is best for you? Read More , all take some time and use varying amounts of system resources and bandwidth.

Leaving them to run while you’re away from your computer, or even scheduling them to happen at night will keep you fully up to date without interfering with any other work you are doing.

You’ll Always Have Access to It

Having your computer turned on all the time enables you to run certain pieces of software that would otherwise be off limits.



This includes remote access software, such as Remote Desktop in Windows How to Use Remote Desktop Connections Like an IT Pro If you work in the IT department of a company that has an internal network, the odds are pretty good that you've had to make use of Remote Desktop once or twice. Remote Desktop is... Read More , or a third party tool like LogMeIn. You’ll never have to experience the frustration of leaving an important file on your desktop at home. You can just log in remotely on your phone, tablet or work computer and grab whatever you need.

Why You Shouldn’t Leave Your Computer on All the Time

You probably turn all of your other electrical devices off when you’ve finished using them. And there are good reasons why you should do the same with your PC too.

Every Component Has a Limited Lifespan

It’s a simple fact that every piece of hardware has a finite lifespan.



A monitor’s backlight is typically rated for a lifespan in the tens of thousands of hours, the capacity of a laptop battery will noticeably shorten with as few as 300 charge cycles How To Care For Your Non-Removable Laptop Battery What precautions should you take to ensure your non-removable laptop battery last for as long as possible? Read More , an SSD is good for around 3000 program/erase cycles Hard Drives, SSDs, Flash Drives: How Long Will Your Storage Media Last? How long will hard drives, SSDs, flash drives continue to work, and how long will they store your data if you use them for archiving? Read More .

In reality, you will have upgraded your computer long before you hit any of these limits. But by leaving your computer on, you are putting it under a constant stress, albeit a small one. It’s also generating heat, and that is one of the biggest factors in reducing the life of hardware.

It Wastes Power

It goes without saying that leaving something turned on when you aren’t using it is a waste of energy. But how much?

A 21.5-inch iMac from 2012 uses up to 56 watts in moderate use. This drops to 44W after being idle for five minutes, and to 18W with the screen off. In Sleep mode, it plummets to just 1W.

watts usage

So, there’s a massive difference between the power consumption of a computer that is active, idle and sleeping. Turning the monitor off saves a large amount of power, and putting it into Sleep mode saves even more. However, in Sleep mode you’ll lose many of the benefits of leaving the computer on, such as being able to access it remotely.

You should also note that a computer that is turned off but still plugged in will continue to use around 0.2W of power. So if you do want to save energy, be sure to pull the plug after you hit the power button.

It Won’t Be at Risk from Power Surges and Cuts

Power surges and power cuts How Power Outages Can Damage Your Computer (And How to Protect It) Unplugging your computer during severe storms? You may want to start. Here's how power outages can damage your PC. Read More are a relatively rare but very easy way of damaging a computer.

Power surges are most often thought of as relating to lightning strikes, but can also be caused by high-power household appliances such as fridges. If the surge is great enough it can cause damage to any electrical items, not least the sensitive components in a computer.


You can guard against this by plugging the PC into a surge protector Are Surge Protectors Necessary? Here's What They Really Do A surge protector is not the same thing as a power strip! Here's how they're different and why you need a reliable surge protector. Read More . These are recommended for general use anyway, but even more so if you plan to leave your computer on all the time.

Power cuts are harder to protect against. It’s possible to buy an uninterruptible power supply (UPS) 5 Things You Need To Know In Order To Buy The Right UPS Power is unpredictable. A car crashing into a pole can cause a blackout or a surge strong enough to destroy most electronics in your home. That's why you need an uninterruptible power supply (UPS). Read More , but these aren’t really intended for consumer use. The hard drive is most prone to damage from a power cut, as this can cause a head crash Do You Really Need to Eject Your Flash Drive (or Device) Before Removing It? It's well known that USB flash drives are supposed to be ejected before removing them. But do you really still need to do this? What happens if you don't? Read More where the disk is physically damaged. It’ll only happen if the disk is in use at the time, so is a relatively minor risk. But a risk all the same.

Reboots Improve Performance

Back in the day, regular reboots were an integral part of the life of a computer user, just to stop the machine from grinding to a halt.

This is no longer the case. Modern operating systems are very adept at managing resources, and if you choose to never turn the PC off, you won’t notice too much degradation of performance.


However, the reboot is still the most effective way of solving many of the day-to-day errors that you’ll encounter. Whether it is an app that is crashing, or a printer that has mysteriously stopped working How To Install A Wireless Printer On Windows & Workarounds Having problems connecting to your wireless printer or looking for a way to make a cabled printer accessible wirelessly? Use these tips and tricks to achieve wireless printing Zen. Read More , a quick restart will often fix it.

Turning your computer off at the end of the day flushes the system and ensures you will start fresh and, hopefully, bug-free the following morning.

It’s Quieter

Finally, and depending on where you keep your computer, you might want to turn it off simply because it is quieter. You can silence the alerts and notifications easily enough, but you’ll still have the ambient noise from the fan, and the clicking hard drive to contend with.

computer fan

Naturally, this won’t be an issue with a modern, fanless laptop sporting low-power CPU and SSD. But for a more traditional desktop system, switching it off is the way to a peaceful life.


There’s no point turning your computer on and off several times a day, and there’s certainly no harm in leaving it on overnight while you’re running a full virus scan How Accurate Are These 4 Big Name Virus Scanners? Read More . A computer will also benefit from being rebooted from time to time, and in the height of summer, it’s a good idea to give it chance to cool down properly.

So, should you leave it on or turn it off? Ultimately, it depends on your needs. If you’re going a few days without using it, then by all means power it down. But if you need it to be up and ready to go at all times, there’s really little harm in leaving it on for as long as you need it.

Do you leave your computer on all the time, or do you only boot up when you need it? Let us know in the comments.

Image credits: Computer night via Peter Varga, Startup items via Intel Free Press, SSD via Yutaka Tsutano, Lightning via Kelly DeLay, Computer fan via George Alexander Ishida Newman

Related topics: Energy Conservation, Sleep Mode.

Affiliate Disclosure: By buying the products we recommend, you help keep the site alive. Read more.

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  1. Anonymous
    July 23, 2015 at 10:49 pm

    Since I use Linux as my OS I don't have a problem shutting it down and starting it up. I don't mind the 15 seconds it takes for openSuSE running the X.F.C.E. desktop to load. And since I don't have any programs setup to run upon login it boots up and loads just fine. Although I cannot say the same for my Windows 8 machine! That takes quite a bit longer to start-up and run. I guess its because there are programs that need to start-up before it gets to the desktop. Either way I think shutting down the PC is "good" for it. At least in my situation, but I'm sure there are Sys ADmins out there who need to access files they store on their home PC's / laptops that would rather keep their machines which case then it's a different mindset.

  2. Anonymous
    July 17, 2015 at 10:21 pm

    All of my systems are on 24/7, however I am not the typical computer user. Most people probably use their computers for email, surfing the internet and other similar tasks. I am retired and my computer is the center point of my entertainment system. Everything I have that does computing from my PC, to my PS3 and PS4 are all connected directly via HDMI to my Yamaha AVR that outputs the video to an HDTV and the sound to my home theater sound system made up of my AVR and Klipsch speakers. I am an avid gamer, a pastime that probably comprises around 50 to 60% of my entertainment, I also watch movies and some TV series via Netflix, Amazon Prime and HBO Go. I also have digitized my DVD and Blueray movie collection as well as my music that my PC is capable of steaming via my network to every device connected to my network. I can even stream movies and music from my PC via a VPN to my mobile devices when I am not at home. I have an Nvidia Shield Tablet that can play games via the internet that are being run on my gaming PC at home due to the Nvidia GPU as well as the provided Nvidia software. When I am not using my various systems for gaming or watching movies etc I do digital media creation on my gaming PC/HTPC that also serves as a high end workstation. I dabble with digital art creation, 3Dmodeling using Blender as well as music creation. Because of this my computer is seldom turned off, I also have everything connected to a good UPS that takes care of power issues, brownouts surges etc. It has enough capacity to preform a safe shut down in the event that I am not at home and encounter a power outage. I have been a user of both Windows as well as Linux for years and all of my computers have been configured to dual boot for several years, I started this back in 2000 if I remember correctly. In spite of the improvements to windows over the years I still find that after around 3 days of continuous use without being rebooted that something stops working correctly, a program that was not completely shut down correctly that does not show up in the task manager but that still refuses to relaunch to some piece of hardware acting weird like the sound card. Once being rebooted everything magically works normally again. The exception to this is Linux, it runs for days without issues.

  3. Anonymous
    July 17, 2015 at 2:34 am

    I turn it on usually when I get up and shut it down when I go to sleep. It's effectively just like a person getting 8 hours a day of sleep.

  4. Anonymous
    July 17, 2015 at 12:22 am

    If you do leave your computers on all the time, as I have for more than 15 years, consider volunteering your extra CPU cycles to solve complex scientific problems.

    Most are cross-platform and many also utilize your GPUs to supercharge the calculations.

  5. Anonymous
    July 16, 2015 at 11:39 pm

    How about putting the machine on sleep mode? I use it regularly, although I must say this method also has its problems. In my case, quite often, after having put the system to sleep, a few minutes later it wakes up again, for no apparent reason. Perhaps a program is having an update, but there is no indication to let you know what is really going on. I would be grateful to have your opinion or even some piece of advice about this specific problem.

    • Anonymous
      July 19, 2015 at 11:12 pm

      Rodolfo - The problems you may be encountering with your PC waking up while in Sleep mode are in a setting:

      Disable the Wake on LAN feature. Essentially, the computer is set to automatically wake up from network traffic, which seems to include pulling out the cable.

      To change this setting, type in Device Manager into the start menu search box, and then browse down to “Network Adapters” and find your network adapter.

      Right-click it and choose Properties from the menu. In the resulting dialog, choose the Power Management tab.

      Uncheck the box next to “Allow this device to wake the computer” to solve the problem. You’ll notice that there’s a warning about having the option enabled in the first place.

      [Need a visual walk-through...see:

      Also make sure you turn off Hibernate mode in WIN XP completely:

      Disable the hibernation feature

      Windows XP's hibernation option allows a computer to copy its current memory contents to the hard drive before shutdown, allowing the system to resume operations exactly where it left off when it was powered down. To do this, it reserves space on the hard drive equal to the amount of physical memory present. If you do not plan to use the hibernation feature, you should ensure that it is disabled, or you are wasting disk space.

      To disable hibernation:

      Go to 'start/control panel/performance and maintenance/power options.'

      Go to the 'hibernate' tab and uncheck the 'enable hibernation' check box.

      If you are using a different operating system than Windows XP, the setting swill be almost the same.


      dun36u9 4Lpha

  6. Anonymous
    July 16, 2015 at 11:37 pm

    If I lived alone I would probably leave my computer on all the time but my wife is a switch it off at night before bed activist and is known to take action if I do not heed the rule.

  7. Anonymous
    July 16, 2015 at 10:48 pm

    Leaving power on all the time prevents temperature cycling of the componentry...
    This is a good thing....In days past, were a major machine killer.

    • Anonymous
      July 17, 2015 at 3:23 am

      A common problem with electronics - power surge on turn-on. Every time any electrical or electronic device is powered up, a momentary power surge occurs. This surge is usually small, but it does stress the electronics, and over time, something fails. It fails because the surge may hit a transistor at just the wrong moment, causing it to overcurrent, and burn out the device.

  8. Anonymous
    July 16, 2015 at 2:51 pm

    The information about SSD memory wearing out after 3000 cycles is incorrect.
    There are two types of SSD memory: Multi Level Cell (MLC) and Single Level Cell (SLC).
    The main difference between the two is their lifespan, the MLC wears out after about 10,000 cycles, the SLC after 100,000 cycles, ten times more than the MLC.
    So only an MLC memory may start slowing down after 3000 cycles, but it will work beyond that.
    About a year and a half ago I asked Apple about the type of SSD they use in a hybrid (a combination of "traditional" HD and SSD drive) iMac.
    They told me that Apple uses only SLC type memory in all their computers.
    Even a computer stays on 24/7 a SLC type SSD drive will last much longer than an old style HD.

    I keep my iMac on, but in a sleep mode all the time. Only once a week I do a cold start of my machine. I don't worry about degrading memory performance.

    • Anonymous
      July 17, 2015 at 12:39 am

      Any worry about a consumer SSD wearing out is misguided. Check out the following endurance test:

      However there is a difference in the reliability of different SSD types. At the moment I would avoid TLC types (three bits per cell) in favor of MLC, but in the end the manufacturers will probably all go that way.

  9. Anonymous
    July 16, 2015 at 9:09 am

    I leave my laptop running all the time, I pretty much use it as a 'desktop' really with dual screens and an external graphics card, it rarely leaves the house now I've got a tablet. I was shocked to learn how much power it uses (around 120w with screens on, 50w without) and started turning it off every night but I just couldn't get into the habit of doing it. I'm running with a Dell Lattitude E6220 with a Nvidia 560Ti external graphics card and 2x 23" screens. Normally I reboot only about once a month or when I start having issues which isn't that often. As others on here do, I also run it through a 750VA UPS primarily so I don't lose work in a power cut but also for surge protection.

    I also run a server for storage which I'd imagine is high on the power usage as it has 8 hard drives in it totalling 16TB, I am in the process of making it more power efficient though and it will eventually go into standby automatically overnight and wake up every morning when it's needed. I haven't measured the usage but would guess it consumes around 150w and goes through a 1200VA UPS for just under an hour runtime in a power cut.

  10. Anonymous
    July 16, 2015 at 9:05 am

    "It Won’t Be at Risk from Power Surges and Cuts"

    That's not completely true, afaik. You are at risk (at least regarding power surges), even when your computer is shut down. The only way to for it to be not at risk when powered down would be to physically disconnect it. Or by using a surge protector, though the cheaper ones probably won't give you complete protection.

    • Andy Betts
      July 16, 2015 at 5:25 pm

      True, you do need to unplug it. I know from painful experience that a lightning strike can fry anything that's left plugged in, switched on or not.

  11. Anonymous
    July 15, 2015 at 8:59 pm

    I leave my computer on all the time. I do a cold start once a week & keep my temp files deleted. Outside of this, I only restart if I am experiencing problems. My HP Pavillion is 5 years old running Windows 7 64 bit. I have 10 TB of storage that I cool with a small electric fan. I do close all my applications every night so files can be backed up. I also have a UPS device that protects against surges and cuts.

  12. Anonymous
    July 15, 2015 at 5:50 pm

    It's a minor point; but there's also security.

    It takes a pretty shit-hot hacker to compromise a computer while it's switched off,

    • Andy Betts
      July 16, 2015 at 5:27 pm

      I think the chances of a random user being hacked are pretty low. Although if your PC is already infected by malware, that's a different matter.

  13. Anonymous
    July 15, 2015 at 2:28 pm

    Whoah, you must be a popular customer.
    The power for the 636 W server alone would cost me around 470€ per month.

    That is the biggest issue when running the hardware all day. Thecost for something you're not even using at the moment.

    My main system is basicly always on when I'm around. I shut it down when I go to sleep or work. Standby or hibernation when I go to the store or do other tasks that don'T take much time. And even with this I still use over 4000 kWh per year which accumulates to a cost of over 100 € per month.

  14. Anonymous
    July 15, 2015 at 1:57 pm

    I keep my computers on all the time. This keeps the motherboard components at approximately the same temperature at all times. Repeated heating up and cooling off of components leads to their earlier failure.

  15. Anonymous
    July 15, 2015 at 1:33 pm

    I shut mine down at night, as well as whenever I'mg going to leave the house for an extended period of time. My husband mostly leaves his on.

    That being said, since when are UPSs for commercial use only? They make home units and we've had one for each of our units for years. They guard against losing work when the power goes out, as well as giving us time to properly shut down so that the equipment isn't damaged. They aren't really that expensive either.

  16. Anonymous
    July 14, 2015 at 10:28 pm

    At work, they require us to keep our computer at night in case they need to install Windows updates.

    At home, I turned it off at night. the computer is set to go to sleep after 20 minutes of inactivity. Also, I scheduled the PC to shut it self down at midnight in the task scheduler if I left on.

  17. Anonymous
    July 14, 2015 at 9:47 pm

    It's not just "on" versus "off". There're also "Sleep" and :Hibernate".

    For me, my PC is either awake or asleep -- seldom "off" -- unless I go for a trip or something.

  18. Anonymous
    July 14, 2015 at 9:44 pm

    There's a PC in my back bedroom with a continuous power draw of 636W (two physical CPUs and fifty three connected disk drives). It takes 17 minutes to boot. It doesn't get turned off voluntarily. Other machines are addressed on a case by case basis. The NUC attached to my TV that uses 6W at idle? It stays on. The Haswell-E desktop that boots in 8 seconds? It can be shut down.

    I manage servers as part of my daily life and I've worked with PC hardware since the mid 1980s. I don't mind eating the cost of electricity and I cope with heat just fine. One thing I will say in favor of leaving a PC on all the time: Computers that are shut down infrequently seem to have far fewer hardware failures in my experience. Maybe the thermal cycle or starting and stopping the motor on a fan or hard disk is the worst thing for those parts, but my experience as a techie and IT guy definitely suggest that staying on is better for keeping hardware working, at least for desktops and servers.

    I do think that laptops should be shut down far more often than most people do, mostly because even fairly small amounts of waste heat will have a larger impact on electronics that are a lot harder to keep cool. I also view a portable machine as one that is much less likely to be essential, but there's also never been a time in my life when a laptop was my only computer.

    • Andy Betts
      July 16, 2015 at 5:35 pm

      I did look into the issue of whether hardware failure is more likely in computers that are started more frequently. I tend to believe that it's true, but suspect that it may just be one of those long-standing myths. There's no real evidence to support the argument, at least not with modern computers.