Safe to leave comp on all the time?

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Posts: 6   +0
I'm wondering if it's better or worse for the computer to leave it on all the time? I'm running a new PC with XP. a P4 2.53Ghz, 512RDRAM, and the rest of the normal goodies. Monitor is a 21" Viewsonic.

Right now, I have all the power settings set to "Never" but my monitor shuts off after an hour.

I've heard it both ways - that it's better for electronics such as computers to be left on all the time instead of turning off and on....or that it's better to save wear & tear by shutting down when they won't be used for a while.

I have DSL, running Norton AV, ZoneAlarm on it.

Any advice appreciated! Thanks!


Posts: 1,310   +0
It is better to leave your computer on as much as possible. The only reason you need to ever shut it down is if you believe your system may overheat due to hot room temperatures, if you need to shut down to install hardware, etc. There is no reason to shut down a PC just for the sake of shutting it down.

Think of your PC like a car. All cars have fans to keep your engine at a certain temperature so that it does not overheat. A overheating car is a very very bad thing. The same reason your PC has a fan so that your CPU does not overheat. If your CPU gets hot enough it will die just like your car engine. When you shut down your PC, all your system fans/cpu fans/etc shut down also. Your CPU literally bakes in the heat and gets hotter and hotter in the last few minutes that your computer is turned off. Then it gradually begins to cool. This is not good for your processor. Lots of cars run the fans after the car is turned off for a certain amount of time so that this kind of thing does not happen. Although you can buy something to make your PC's fans stay on for 5,10,15 minutes or so after shut down. Normally a PC does not do this.

Also I don't know where you heard about the "wear and tear" idea, but shutting down your PC is what would cause "wear and tear" (if there is indeed such thing with a PC). Leaving it on would prevent this, not cause it.

As long as your PC is running at a decent temperature, leave it on.


Posts: 135   +0
This is a very important thing to consider.

Actually, the BEST thing for your computers longevity is to leave it on once it's on. Obviously during thunderstorms and upgrades you can't, but there is a reason for this.

Nowadays with all the extremely fast processors and Graphic cards running under 450 W powersupplies, a LOT of heat is produced. This leaves something to think about. Consider this:

When you turn on your computer, everything heats up, causing, logically, everything to expand from the heat. Much like gas. It's miniscual at best, but cards and boards DO expand. Now, when you turn OFF the computer... it gets cool again, which makes the boards etc contract. So putting it in this loop of expand and contract CAN (not 100% of the time naturally) damage components inside the system.

I would recommend ALWAYS leaving the computer on, and although I can't say anything in my system has broken due to what I described, I'd like to mention that I've never really turned off my computer once it's up and running.


Posts: 6   +0
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Thanks guys. Great responses so far - it looks like I'll be able to leave my computer on with no problems indefinetely.

Right now, I'm not concerned with the box getting too hot. The room the machine is in doesn't get too hot, and I'm not running any high-end video cards or anything else that will generate a lot of heat. It's a Dell 8250 and a very quiet computer, I can't even tell it's on, and can't even hear the hard drive running when I'm doing something. The noise won't bother me.

So, I guess I'll just continue to have my monitor shut off automatically after an hour or so and let the computer stay on and connected unless I need to do some maintenance.



Posts: 1,310   +0
Were not saying it will hurt your system turning it off every night, and it depends on how long you use the computer. Ten years down the road yes you may have problems, but its also possible to have problems 2 years down the road due to turning off the your PC every night. You can't really tell. It is just a lot better to not turn off your PC when you dont have to.


Posts: 1,519   +1
In this thread I see a classic case of misrepresentation of facts through association, and analogy, with unrelated devices. This is due to not understanding the underlying reasons why certain devices fail.

Please note that a PC is NOT a car (which requires lubrication), and neither is it a lightbulb (which has a filament that is subjected to rapid cycling of very high and low temperatures). It is an electronic device with some mechanical parts, both of which wear with use.

Note that cars will wear with mileage, and additionally during startup, when lubrication is lowest. Lightbulbs suffer great stress when being switched ON/OFF due to very rapid heating/cooling of the filament.

Electronic devices wear through use due to electron migration caused by current flowing through the device. More current means faster wear, and increased temperature also results in faster wear (electron migration is increased by temperature). Switching ON/OFF does NOT create wear, and is what digital circuits are doing rapidly all the time.

Mechanical PC devices, such as fans and hard drives wear with use, and do not wear when switched OFF. Motors on hard drives are rated for around 50,000 ON/OFF cycles (e.g. 10 times per day for 13 years), but hard drive bearings will fail after around 5 years due to the lubricant drying out and the bearings becoming worn. Lubricant dries out faster at elevated temperature (i.e. during operation). The drive electronics should last much longer than the mechanics, though these, as with any device, are subject to manufacturing defects which can cause sudden unexpected failures.

Conclusion: PCs will last longer when switched OFF during the long periods when they aren't being used (e.g. at night). Period.


Posts: 1,310   +0
Nick, you obviously have no idea what you are talking about. Consult your local scientist OR 2nd grade teacher for the true facts.


Posts: 1,519   +1
I know a lot more than my second grade teacher.

I used to carry out defect investigation of electronic modules way back when I worked in the defense industry, and I studied the subject, so I am in fact already an expert on these matters. If you don't wish to agree with my statements, that's perfectly ok and it doesn't much matter to me. I only inform, its up to you what you choose to believe. ;)


Posts: 896   +0
Originally posted by ---agissi---
I guess my PC is pretty screwed considering I turn it off everynight :( won't be that bad. My old P166 is still working after 6 to 7 years. I never left it on the whole day always switching it on and off, sometimes up to 5 times a day.


Posts: 914   +0
I am again going to dispute the rising in temperature when powering off the PC - IT doesn't happen. Once no more current is running through the system, no more heat can be output - therefore, no stagnant gain in heat. At most, the system can stay at current temperature for a long duration. The remaining heat not being dissapated would be a sign of an improperly designed heating system in the first place. You can't generate heat from nothing.


Posts: 1,519   +1
I agree with SH, there is no way that temps can increase in a PC after power off. If you have a lot of case fans, with a large air flow, then the temps might 'slightly' increase (probably not noticeable) due to no moving air (moving air has a cooling effect).

This is different from a car, due to the fact that when a car is stopped, there is no longer any cool air rushing through the engine compartment so the heat built up in the engine will soon migrate to other engine parts (which will see a temp increase).

The hottest parts will always decrease in temp as soon as power is removed.


Posts: 512   +0
hey guys, you're arguing without real purpose
all the hardware will be trashed 5 times before it's worn !!

we're on a geeky comp site, so everybody is upgrading all the time, and even most of us might leave the "old" machines running, they will still be probably totally outdated before they break because of switching on/off


Posts: 914   +0
Originally posted by videobruce
When not in use, turn off the juice!

Stop being a natural resourse hog. Lets not all be like California.

It's impolite to double post. You posted that exact same post in meeting spot... sure these are similair threads, but that's aside from the point. :)

And, a few of us produce our own power!


Posts: 37   +0
Speaking of shutting down computers, until it reaches what temperature should you consider to be overheating and shut it down?!
ok for all you guys out there asking whether its safe or not to leave your computer on forever- stop askin questions and try it yourself

go ahead, and you will see just as i did that its not harmful for your computer, but neither is it good. leave your computer on for 2 weeks and watch a 3.4 ghz slow down till you cant even play a half decent game on it

processors heat up. the fan is not designed to cool it down, its designed to keep it at a core temperature, but regardless of this, it still keeps heating up very very slowly - go ask any technician, go see it yourself - fans are useless and ridding this built up heat

so in answer to everyones question, yeah its safe to keep it on. but it does slow down your computer a LOT.


Posts: 1,929   +15
Leaving your PC on slows the cpu down??? HAAHAHHAHA

Wow this is a REALLY REALLY old thread... last time i shut down my PC everynight was like a year ago or probably more, i always always leave it on every single night.


Posts: 4,909   +8
I leave all my stuff running 24/7, its never done any harm. Naturally, you want to enable power saving on monitors and so forth, but that's it. I once had my Linux box have an uptime of 142 days.


Posts: 90   +0
videobruce said:
When not in use, turn off the juice!

Stop being a natural resourse hog. Lets not all be like California.
If you are running a newer PC and have ACPI funcitonal correctly on all your devices you can drop the usage of joice to almost nothing when it's asleep. It is true if it's off, less juice but if left on with the condtions above you will not use that much at all compare to Win9x.

But from a purly power consertive view off is better but in the above case not by too much.

I generally turn my off at night but due to my increase downloading (which takes days for one file...) I've left it on for days recently too.


Posts: 237   +0
I never really shut down my computer, but I have noticed it getting slower. Not sure if it's because of not shutting it off, or leaving AIM on all the time! (Hahaha!) Or if I just have a virus. But my computer is also crap, so. I'm not too sure! I need to get new parts for this computer really bad anyway, and I can't even play WarCraft 3 on it anymore....
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