An idle desktop computer can use 70-100W of power, even with the latest power saving hardware. That's a huge waste. If you're worried about the time it takes to start back up, use a sleep or hibernate mode. It's like saying "I leave all the lights on in my house because flicking the light switch is too much work."

As for components like hard drives, these can fail whether you leave your computer on or not. Hard drives especially. Always keep a backup.

I leave it on. I schedule all sorts of updates/scans/de-frags in the wee hours of the night. That way all that system maintenance is done while I sleep, and I can do more cough productive cough things when I'm actually at my machine.

Essentially, my time is worth more to me than a small amount of wear on a hard drive or power bill.

I'm absolutely appalled by the majority of the answers given here. Don't any of you care about the environment? Electricity doesn't come out of the socket without an impact on the Earth's resources, you know.

If you're not using it then switch it off!

Sleep mode does wonders if you want it to boot fast and save some power etc.

For the rest I don't think you will still use your computer by the time you wear out your hardware by rebooting every day. So I would just shut it down if you go home or go to bed.

I think you should just set up sleep/hibernate mode properly, and forget about the issue. Most modern machines know not to sleep when a long-running operation is running (e.g. download or defrag).

Two arguments for this:

• Power waste. It adds up. 200 watts all the time is same as keeping 6*100w bulbs burning every night -- with higher efficiency bulbs, you can light up your whole house for the same money.
• Saving state. When the computer goes to sleep, Windows also saves the state to hibernate (in W7, not sure about Vista). This way, if power goes off, it will resume from hibernation, with all your work still there. Very nifty feature. If you keep the machine on (with programs open) and power goes off, any unsaved work is lost.

For me, it comes down to this:

• If that night I need torrents, backups, etc, that need to run, I keep it on.
• Otherwise, turn it off. I've had the same hardware in my server/desktop for almost 4 years now doing just that and I've experienced no issues.

Leaving your computer on all night while it isn't doing anything useful is a simple waste of resources.

You should have it always on in case I might need something from it :)

I turn my machines off ...

saves power

less heat

less noise

better security (remote rather than console)

No, turn it off.

What computers do when they're on and not doing anything:
- waste electrical energy (which is not that negligible) <-- nowadays, wars are fought over energy, remember ?
- produce heat (which is not that negligible)
(neither of these are making our planet a nicer place to live)
- cost you money

What computers do when they're off:
- don't cost anything
- helps to ease up that air condition unit
- most of their parts are not made up for 24h work load

Hard discs do not suffer that much from turning off/on, as has been presented here. I've got three of them in the drawer/attic, which range from 15-10 years old, and have been turned off/on, regularly for 10 years, several times a day. All still work (I'm not using them of course, but they still work).

The price of energy has been calculated by someone already.

I turn my computer(s) of in the evening .. I sleep in the same room and the noise drives me up the wall ...

I'm also the person paying the utility bill ..

I leave mine on unless I am going to be away for 2 days or longer. With EnergyStar(TM - Whatever) components and the proper power settings the difference in energy costs is negligible. My main concern is the wear/tear on the HD from spinning up and down and changes in temperature.

This is a good link - Turn the PC off or leave it on ^[1]?

It depends on your definition of "better".

I normally turn my PC off at night and when I'm at work because of the power issue. Whether or not electricity is cheap where you live, that still adds up to a large amount of energy. Considering that we're now being told to switch off devices like TVs and DVD players at night instead of leaving them on standy, when their standby power comsumption is only in single digits, the idea of permanently leaving on a 100+ W device seems incredibly wasteful.

Now, in the 10 years I've owned a PC (and maintained other people's), I'm not aware of any hard disks failing purely because they've been turned on and off too much. I certainly remember hearing in the past this argument for not turning PCs off unnecessarily, but I'm not convinced that this is still the case.

So my point is: unless the PC needs to be on all the time, is the damage to your bank balance/damage to the environment/minutes saved in not booting (delete as applicable) really worth it?

No, turn it off. E.g. if you know you will not be using it for the next two hours or more (unless some background process is running - like defragmentation or downloads).

The power cycles will definitely shorten the life of the harddisks and other components, but your computer will be outdated long before the harddisks die. In any case you should take steps to ensure a harddisk failure will not affect you (backups and/or a RAID system, etc.).

Leaving it on is an unnecessary waste of resources, regardless of wether you or your employer pay the electricity bill.

It's generally better for the computer to leave it on all the time, if you can afford to.

Most wear and tear on electronic components occur during electrical surges when the devices are turned on and off (and during line surges if you aren't running behind a surge suppressor/power filter). For hard drives, most mechanical wear happens with the drive spins up and spins down. Avoid these two events as much as possible and you will maximize the lifespan of your computer.

The problem I find with turning it off is the time it takes to boot. But there's a solution.

In many modern computers, in the BIOS (hardware settings), you can set a time for the PC to automatically power on.

I have this set to 6 a.m. or so. And I use TweakUI to automatically log on.

So I power down every night, but when I get up in the morning, my PC is already on, booted, and ready to use.

I think you've answered your own question! If you are worried about cost and don't use the PC remotely or for schedules then the power usage on a high power machine MIGHT be higher than the cost of replacing the odd hard drive every few years.

For cheap components, power cycles are very stressful but for quality goods with good soldering and proper heatsinks + thermal paste etc I doubt you'd see much problem.

Having said that, very high end enterprise grade equipment doesn't get power cycled at all so they are probably made without that in mind! I don't plan to reboot my SAN more than once a decade!

Yes. If you turn it off, you have to wait for it to turn on again.

In all seriousness, this is why I leave it on. The hardware will have to fend for itself.

My desktop is left on all the time because I run some servers on it (like MagicJack, SVN).

My laptop is always put into Sleep/Suspend mode when it's not used. I, personally, think that you should never "Shutdown". You should always sleep or hibernate your computer. There's really no reason to shut it down and restart it except for updates.

You can nullify the HDD wear by either having the drives turn off when your machine is idle for more than a few minutes, or by using a SSD.

I usually leave my system on. It produces nice white noise that helps me sleep and I can keep my work open so I know where I left off when I start work again tomorrow. If I turn the machine off, I will likely forget something I was doing prior to going to bed.

I do turn my monitors off, though, whenever I leave my machine. That's 200 watts of power easily saved.

I used to turn my machine off at night for a couple of reason. It would heat my room beyond a comfortable temperature. Also, the fans collect grime faster if they're churning through more air.

I setup the monitor to power-off when idle for sometime.
Otherwise, at least one system is on at all times.

I used passive cooled components on one of the machines to keep noise low
so it could be kept on for extended periods.

But, if possible, I choose to turn them off.
Specifically, I let the laptop hibernate when not in local or remote use.

Work desktop: I turn it off, so I will

• make sure I save everything and tie up the loose ends before I go
• have a clean start the second day
• don't waste energy; it's not mine, but I no longer feel comfortable wasting it

Personal laptop: I leave it in standby when not used.

Media center: It's off when not used.

Personally I turn my PC off at night.

Essentially, my time is worth more to me than a small amount of wear on a hard drive or power bill.

I used to feel the same way, back when I was still in college and I used my PC all day.

However, now, I have a real day job (scary!).

I turn my PC on in the morning, check email and whatnot before work, and all my defrag / backups / etc complete while I am at work. This way I can also remote desktop from work if I need something important from my home machine.

Frankly, I don't have nearly enough automated tasks that I need my PC to be running all night and all day every day.

Sleep / Hibernate / Shutdown it. Leaving it on without anything to do, would be like leaving your car turned on all night in the garage because you don't want to turn it on the next morning…

Don't be lazy ;)

A couple of things.

Yes, leaving your machine on uses power, wears out mechanical moving parts (fans, mostly) and leads to more accumulated dust and nastiness inside your PC, which can cause airflow problems (this is why you shouldn't keep your computer on the floor). Windows isn't really designed to run all the time without a reboot, and memory leaks are still depressingly common - depending on how you use your PC, you may find it feels a little more responsive after a reboot.

Some components inside your PC will last longer if left running permanently, and some will last longer if they're turned off when not in use. The debate over what will last longer isn't really anything to worry about, since by the time the components have run for long enough for this to become an issue, they'll be obsolete anyway.

Having said that, if you're going to leave your PC on overnight - say, for a hefty torrent download - then if you're feeling energy-conscious, you might want to have a look at this link ^[1]. World Community Grid will allow you to donate your unused CPU cycles to help develop the next generation of solar cells (IE "solar cells that are more useful than the ones we have right now - which really aren't terribly useful at all"). This is exactly the sort of thing that's useful for people who leave their PCs running permanently.

They do other research as well; check it out, it's very interesting.

I have frequent need for ad-hoc access to the desktop throughout the evening and I frequently run stuff overnight, so I run 24x7.

I place all my peripherals on a separate power-strip however, and simply flip the switch to disable the displays, speakers, and nearby lights.

In the triology "Night's Dawn Trilogy", Peter F. Hamilton said (quoted from my poor brain):

Climate really got worse after the invention of fusion power. The next day, power was so cheap, everyone got air conditioning. For several months, billions of watts of heat were pumped into the atmosphere. On June 2346, New York City was hit by a hurricane with wind speeds over 300 miles per hour. 75 Million people died. In the following years, all cities on earth had to be covered with domes of the wind would have just ripped them away.

So while you can do it and simply ignore the effects, the effects won't ignore you.

First and foremost, the reason there are two sides to this issue is that both arguments are correct. I will just add one factor to the mix .... if you live in an area prone to thunderstorms during a particular season, definatley turn the PC off when not in use. I go as far as removing the surge protectors plug from the outlet during the springtime, as we have frequent and powerful storms. The rest of the year, I leave my PC on as my motherboard and operating system have features to conserve some electricity, and I feel the "wear and tear" factor is real.

Keeping your computer on all the time is (I believe) a hold-over from the olden days. Way back when there were vacuum tubes and then the advent of those delicate transistors and flip-flops, keeping power applied all the time was necessary to reduce spikes and wear and tear on these sensitive electronic parts. Turning your gear off and on was a no no. This process was carried over to the first desktops (Apple II's, Lisa, etc.) and perpetuated through misinformation and ignorance.

The electronics in today's computers are much more hearty and reliable; consequently, not with standing individual need for updating and number crunching during the wee hours, it is not necessay to keep your computer on when it's not in use. Also keep in mind that memory is refreshed at boot-up and malicious software using your computer during the night is also eliminated when you shut down when the computer is not in use. Savings on your power bill is another plus - businesses with many to hundreds of computers seldom require employees to turn their computers off at the end of the work day; imagine the energy savings if they would.

If you're worried about your computer overheating when you turn it down, some power supplies out there actually spin for a minute or two after shut down to exhaust all your hot air.

I'm not sure if they do or can run your fans as well, but this is a possibility.

If you can find a power supply that will do it (or even just a battery), you could wire up a circuit using a 555 timer chips that runs the fans for about 30 seconds after power off.

I leave mine on. Partly it's because I loathe re-setting-up my desktop all the time, but the maintenance issues you touch on are in there. As far as I can tell, it's just a universal property of systems like these that starting them up and shutting them down is far harder on them than time spent running in a steady state. Some kind of chaos theory phase transition thing going on in there, I'm sure.

I leave my computer most of the day and just hibernate it when I am out or sleeping.

But no need to keep it working all the time, sure closing it will increase the hardware life time.

It depends on what you are going to do with the PC. For example, if I am out of town doing business, I leave the one on that can be accessed by using Go To My PC. This gives me the option to access my hard drive if needed. Then again, if I not on a business trip, I turn off all computers, because the black hats may try to access them. Most of the time I leave them off unless I am expecting some incoming messages. For those who like leaving their computers on, put your modem in standby-by. This should stop intruders. If there is the possibility for electric storms, turn off and unplug. A surge protector should help and if you do not have one, please get one. ChasNic

24/7 COMPUTER USAGE ADVANTAGES

a) No booting up time wasted

b) Less time wasted

DISADVANTAGES

a) Wastes Power/Energy

b) Hardware failures ( it would fail automatically even if pc is turned off : dust particles etc... )

c) Memory usage increases

SOLUTIONS

• Hibernate/standby if you want to keep pc on 24/7

• Turn off pc when its completely not in use!

Bah I leave my computers running all the time even my laptop is rarely shut down, though I let them turn of the displays as those are much more power hoggy.

It depends. It is like keepping the engine of a car on when you are stoped, if you plan to move in one minute, better to keep it on, but if you are one hour, better to stop the engine.

When you go to bed, I think it has no sense to let the computer on until next day, and worse if you go on holydays...

I vote better to switch off (in normal circumstances).

It seems to me that there is no "one answer fits all". The most intelligent decision would be based on the INDIVIDUAL's amount of daily use of his/her computer. An infrequent user, for example, would receive no benefit from having the PC running in active mode constantly. On the other hand, someone who is frequently at their computer might determine that a "sleep mode" is most efficient and effective. Having the PC in full operation mode all night when it is doing nothing provides no advatage, but does cause needless wear and tear and costs. It is not an "either/or" answer for all users; different scenarios present different solutions. Do the math. Trust your intelligence.

If there isn't a particular reason it is essential to leave it on all night, the trade-off between sleep mode and power down is tricky. Power down/up is harder on the hardware, but it uses less energy. (On a Mac mini, assuming 8 hours sleep, shutdown uses about four watt hours and sleep uses about twenty.)

Whether it's better for the environment (and your bank account) to spend more energy in the short term and have your computer last longer is a fairly open question. If you're the sort of person to replace individual components as and when they die, or if you replace your computer every few years anyway, I'd lean towards switching it off. However, if you prefer to stick with one machine until it stops working and then completely replace it, leaving it on may be a better option.

Try to find the power consumption of the machines in question. This should help you make a more informed decision.

For those advocating switching off computers to save energy, be aware that most computers and appliances consume power even when switched off.

Anything that uses a power transformer to convert electricity or is "instant on" consumes standby power ^[1] even when switched off. To prevent this you must physically unplug the appliance from the wall socket, or plug them into a switching power bar which you switch off after powering down the devices plugged into it.

Even Energy Star devices consume power when switched off.

Unless you need the machine to be up (e.g. a server) shut it down and use less electricity.

I think that leaving it on depends on how much power your computer uses. If your computer uses a lot of power than you should turn it off. My computer doesn't use a lot of power so I leave it on but I put it into standby.