[iDave]

Is it ok for the iMac if I leave it on for a couple of days without it on sleep?

[italiano]

Originally Posted by iDave

Is it ok for the iMac if I leave it on for a couple of days without it on sleep?

I leave mine on 24/7 - no sleep - just screensavers. Won't hurt anything

[genesisdan]

Laptops too? Waiting for delivery of my 15" PB and was curious to know as well....

[harrisjamieh]

Its ok, but in theory if you think about it, it should decrease the life of your computer, as the components are constantly on, and all components have a finite number of hours they will work before failure. The problem with leaving a laptop on would be that you would have to have it plugged in quite a lot to leave it on over night, which would damage your battery. Its much better to simply close the lid of your new powerbook to send it to sleep, doesnt take much effort

[genesisdan]

ok, forgive my ignorance, I am a mac convert

on the windoze corporate side, I was always taught that the shutdown and particularly startup wear-and-tear on a pc was worse then just leaving it always on; after a while, whatever your settings were at, your hard disk would idle out and since it wasnt spinning, wouldnt consume as much power. Also, since you left it on, when you went to use it the next day, it was immediately available to you without going through the boot process.

is that a load of hogwash? does that not apply to macs (I thought a drive was a drive).

Again, please forgive the ignorance here... i LOVE these forums

[moodymonster]

leaving a pbook plugged in round the clock won't damage the battery - it will not overcharge, when its charging the plug glows orange, when charged it glows green. Every month or so it is good practice to run it off the batttery to the point it goes to sleep - this lets the battery calibrate itself. I have my powerbook plugged in overnight and then some, have done for years, battery is still in good shape.

The battery can get damaged (develop a 'memory' effect) if you leave it plugged in all the time because the battey will naturally loose charge over time, if it is always plugged in, after a few weeks it will drop below 90/95% charge, it will then start charging. Over time this will result in the battery seeing its capacity as 90/95% ie only 10/5% of its actual capacity. Fully discharging and fully charging it up once a month recalibrates the battery so it sees it full capacity.

There is a school of thought that the wear and tear of startup will reduce the life of components but given that the very same components will spin themselves down - ie do what a sleep would do - it seems pointless to leave it on and running all the time.

I leave my mac on all the time, and sleep it when its not in use. I think my pbook's only been shutdown twice in 2 years. Desktops - on, and asleep when not used - last 4 years.

Being on round the clock won't harm it - but consumes more electricity.

Sleep essentially lets you save electricity while being able to get back to where you last had the computer, in the time it takes you to push a key.

[ghporter]

Genesisdan, you were told old information from your Windows folks. ANCIENT information, in fact. Because there were failures in things like drives (we're talking about MFM drives from 20 to 25 years ago!) the "common wisdom" was that you should leave things on 24/7. Except that all Windows OSs, even 2K and XP, have issues with memory leakage-and it's typically MS applications that do this-so they need rebooting on a regular basis. In the corporate environment I used to be part of, the computer was required to be turned off after business hours-leaving it on was a bigger waste of energy than any potential savings of wear and tear.

Harrisjamieh, your arguement is also "old data." While you are wearing down a finite resource, it's not a brief and precious resource. I have hardware that's 10 years old and still runs fine, well after it should have been replaced by newer technology. Today's hardware typically has expected lifetimes in the six figures of hours. You can run a new computer (particularly a Mac) constantly until it's so outdated it isn't terribly useful and still not wear it out.

Moodymonster, modern batteries in modern computers don't suffer from the memory effect. That's something associated with nickle-cadmium batteries, not the lithium-ion batteries Apple (and almost everybody else) puts in new computers.

iDave, the only thing bad about leaving your computer on and not sleeping is that it uses more electricity. Within the (technologically) useful life of your iMac, leaving it on won't hurt it.

[moodymonster]

li-ion batteries may not suffer from the memory effect but still need to be 'exercised' once a month:

http://www.apple.com/batteries/

A Ti G4 I had developed essentially a memory effect due to not cycling the battery once a month. Since then I've always done it.

[mduell]

Originally Posted by ghporter

Except that all Windows OSs, even 2K and XP, have issues with memory leakage-and it's typically MS applications that do this-so they need rebooting on a regular basis.

ghporter, you were told old information from your Windows folks. ANCIENT information, in fact. Because there were leaks in earlier versions (we're talking about 9x from 5 to 10 years ago!) the "common wisdom" was that you should reboot Windows regularly.
While applications (on all platforms) leak memory (*grumble* Firefox 1.5 *grumble*), you can get it all back in Win 2k/XP (and OSX and Linux) by closing and reopening the app.

Random non-significant sidenote: While googling for memory leaks, I found that "OSX memory leak" has 1.6m hits, "Windows memory leak" has 1.69m hits, and Linux takes the cake with 1.95m hits.

[quiklee]

why not? I leave my computer on all day because i heard that turning it off and on causes power spikes in the components which seem harmless in the beginning but can take its toll - something like electronic water torture! =)

[far200]

Originally Posted by iDave

Is it ok for the iMac if I leave it on for a couple of days without it on sleep?

sure......
why not try to put it in sleep mode if your not using it...
you'll save some power that way....

[mduell]

The number of myths and amount of voodoo about shutting down/starting up vs constant running is rather amusing. I have yet to see anyone link too an actual test.

I leave my computer on 24/7, but it sleeps if its not doing anything.

[iDave]

Another question, I am leaving for 2 weeks should I leave it on the Screen Saver for that long?

[rjenkinson]

if you're leaving for 2 weeks, just turn the thing off. save yourself some money.

-r.

[Steve]

Why wouldn't you just sleep/shutdown? It's still using energy, and would only be necessary if you're running some sort of application full-time.

It won't, however, harm anything.

[davo]

I have just set my power button to send my machine to sleep. So when i am going to bed i push the button once and it goes off to sleep. In the morning move the mouse and it is awake with seconds.

[ghporter]

Originally Posted by Steve

Why wouldn't you just sleep/shutdown? It's still using energy, and would only be necessary if you're running some sort of application full-time.

It won't, however, harm anything.

I stopped preaching about how much energy you save versus how little time it takes a Mac to boot a while back. Nobody listened. Yesterday's paper had an article about how much electricity "instant on" and sleeping equipment actually uses; in some cases nearly 12% of a residential electric bill can be for DEVICES THAT ARE NOT ACTUALLY ON AT ALL but merely sitting there waiting to be turned on.

I turn off everything I'm not actively using (except for my network hardware and that only because it's hard to reach the UPS to turn it all of with). This includes PCs AND Macs.

Ok, I'm done preaching again.

[SpaceMonkey]

Originally Posted by ghporter

I stopped preaching about how much energy you save versus how little time it takes a Mac to boot a while back. Nobody listened. Yesterday's paper had an article about how much electricity "instant on" and sleeping equipment actually uses; in some cases nearly 12% of a residential electric bill can be for DEVICES THAT ARE NOT ACTUALLY ON AT ALL but merely sitting there waiting to be turned on.

I turn off everything I'm not actively using (except for my network hardware and that only because it's hard to reach the UPS to turn it all of with). This includes PCs AND Macs.

Ok, I'm done preaching again.

But but...my uptime!

I love it when people brag about their uptime, even though they don't have any real need for their machine to be running 24/7.

[imitchellg5]

Leaving it on shouldn't be a problem, especially since screensavers don't really save screens anymore. The Macs at the local Apple Store are on 24/7 also.

[P]

Originally Posted by ghporter

I stopped preaching about how much energy you save versus how little time it takes a Mac to boot a while back. Nobody listened. Yesterday's paper had an article about how much electricity "instant on" and sleeping equipment actually uses; in some cases nearly 12% of a residential electric bill can be for DEVICES THAT ARE NOT ACTUALLY ON AT ALL but merely sitting there waiting to be turned on.

I turn off everything I'm not actively using (except for my network hardware and that only because it's hard to reach the UPS to turn it all of with). This includes PCs AND Macs.

Ok, I'm done preaching again.

The problem is rather that since it takes time to boot the Mac, short as it may be, people tend to put off shutting it down. If you are disciplined enough to turn it off as often as you would put it too sleep, then you save energy, but most people are not that disciplined.

My iMac G5 uses 100-120 W while idle, 10W while sleeping and 2W while shut down and plugged in, or at least that's what my Googling finds on a similar model. The energy gained while having the machine shut down and not sleeping is quickly lost if you avoid shutting it down over short periods.

[FireWire]

Originally Posted by genesisdan

ok, forgive my ignorance, I am a mac convert on the windoze corporate side, I was always taught that the shutdown and particularly startup wear-and-tear on a pc was worse then just leaving it always on

Originally Posted by ghporter

genesisdan, you were told old information from your Windows folks. ANCIENT information, in fact.

I'm a little bit puzzled to see this because that's what I've been told, and that was always on the Mac side. Incidentally :

Originally Posted by quiklee

why not? I leave my computer on all day because i heard that turning it off and on causes power spikes in the components which seem harmless in the beginning but can take its toll - something like electronic water torture! =)

I've read the exact same thing. In fact, that's the same reason why you seldom see a lightbulb burn while in use, but often the instant after you turned it on. Furthurmore, the heat produced by the current flowing causes the expension of the components, which is reverted as the product is turned off, causing a shrink-expand effect, a phenomenon which causes important damage to our roads here in Québec, as the seasons change. The constant movement weakens the connection and the solder joints, which will eventually fail sooner than if the computer was left on but in sleep mode, which would lessen the spike experienced on startup.

I think that nowadays, computers are meant to be left on all the time, but with the sleep option enabled. I guess that's why the power button on my flat panel iMac is located in the back, in the most inconvenient position: we're not supposed to use it much. Wasn't there a rumor that Steve Jobs wanted to get rid of the Shut down... option from the Apple menu to encourage use of the sleep mode?

Nonetheless, I would recommend to turn off your computer if you're leaving for two weeks or a long period, because there could be a grid shutdown by your utility company, or an electric storm, which could damage your machine while you're away.

[jamil5454]

Originally Posted by imitchellg5

Leaving it on shouldn't be a problem, especially since screensavers don't really save screens anymore. The Macs at the local Apple Store are on 24/7 also.

Just for the record, the Macs at the Apple Store are shutdown at night and booted early each morning. They're set to boot from a master OS X image on the store server every morning.

[ghporter]

Originally Posted by FireWire

I'm a little bit puzzled to see this because that's what I've been told, and that was always on the Mac side. Incidentally :
I've read the exact same thing. In fact, that's the same reason why you seldom see a lightbulb burn while in use, but often the instant after you turned it on. Furthurmore, the heat produced by the current flowing causes the expension of the components, which is reverted as the product is turned off, causing a shrink-expand effect, a phenomenon which causes important damage to our roads here in Québec, as the seasons change. The constant movement weakens the connection and the solder joints, which will eventually fail sooner than if the computer was left on but in sleep mode, which would lessen the spike experienced on startup.

I think that nowadays, computers are meant to be left on all the time, but with the sleep option enabled. I guess that's why the power button on my flat panel iMac is located in the back, in the most inconvenient position: we're not supposed to use it much. Wasn't there a rumor that Steve Jobs wanted to get rid of the Shut down... option from the Apple menu to encourage use of the sleep mode?

Nonetheless, I would recommend to turn off your computer if you're leaving for two weeks or a long period, because there could be a grid shutdown by your utility company, or an electric storm, which could damage your machine while you're away.

Modern computers are built so that they MAY be left on permanently, but not because they MUST be left on. The roads in Québec (and in Michigan, where I grew up) are much more rigid and subject to much more extreme thermal stresses than a computer's components. Computers are built to manage their thermal output, which allows them to remove their excess heat while on, and to quickly, though not suddenly, reach ambient temperature when turned off.

Complex electronics are absolutely NOT analogous to light bulb filaments. Further, your understanding of the sudden failures of these filaments is incomplete; they fail when turned on NOT because of thermal stresses, but because the AC frequency resonates the filament as it runs through it, and when it stops, the filament (white hot, remember) may be kinked or otherwise left in a weak configuration. When the power comes back on, the 60Hz, 120V power heats the filament in microseconds, and the weak spot fails because it is weak.

Frankly, your lack of confidence in solder joints is plain wrong. A solder joint is not merely "glue" using molten metal. It's a very complex interaction between the solder alloy and the metal in both the component leads and the circuit board pads. And a wave soldering machine makes exceptionally good joints every single time, unlike a human with a soldering pencil, who can make mistakes-even different mistakes on every connection he or she solders.

Finally, a substantial portion of every North American's power bill pays for "instant on" devices that soak up power while doing absolutely nothing except waiting to be turned on. This is an obscene waste of energy, particularly when so many people believe that our entire fossil fuel dependent-society is in for a sudden shakeup within the next decade/generation/our lifetimes/(your favorite pessimistic prediction here). I for one believe that if I'm not USING a device, then IT shoud not be using power.

I'm not trying to scold you personally, honestly. But there is so much FUD about "leaving Macs on because..." that every now and then someone has to step in and point out reality. Most "stay on" arguments, by the way, talk about specifics of hard drives starting up-which was true (maybe) in 1984, but is certainly NOT true today.

Bottom line: leave it on and sleeping if you want, but you'll use much more power doing that than waiting 30 seconds for your Mac to boot tomorrow morning. Honest.

[leery]

People were asking this question 20 years ago. There was no consensus then, even in the "ancient" times. As far as hardware, it is now as it was then: your computer is a complex machine made of many parts, and for every part that would benefit from daily shut down, there is a part that wouldn't or even suffer. You'd be surprised, too. I've had RAM modules that failed after a few years, but my 10 year old floppy drive still works fine. Your modern PC should last years, whichever way you go, so do whatever works for you. Now, all you smartass kids be quiet, it's past my bedtime!

[FireWire]

Originally Posted by ghporter

Further, your understanding of the sudden failures of these filaments is incomplete;
[...]
Frankly, your lack of confidence in solder joints is plain wrong.

Well, I don't believe that there is a direct correlation bewtween the two, but it was more an analogy to explain the phenomenon. Thou I didn't know about the oscillation you explained. Plus, I'm not saying that the solder joints will fail after 3 months or years, but that if given the choice, it's better to leave it on and keep an even temperature (and thus dilatation) than to give it a thermal shock everyday, which can potentially damage (or weaken) it in the long run. Like you said earlier, the equipement will probably be obsolete by the time it makes a difference, but why take the chance. We're talking about parts and wires that are only a few microns wide, that can be damaged by the static electricity of one person if touched when not grounded!

Originally Posted by ghporter

Bottom line: leave it on and sleeping if you want, but you'll use much more power doing that than waiting 30 seconds for your Mac to boot tomorrow morning. Honest.

Of course, but as I understood the original poster's interrogation, I thought that he was more concerned about the machine's physical "integrity" than the environnemental implication, but you are absolutely right that it's better to turn it off to preserve energy. However, as I understand it, I think the iMac (and other models) was designed to be run at all time, with a very low power consumption when idle. Plus, the maintenance tasks are scheduled at time when most people are still asleep, and would have to be run manually if the computer is off, and only started up when needed. I never thought that it was a matter of saving time, but simply to "preserve" the computer.

[ghporter]

FireWire, as I said, I wasn't tearing into YOU specifically, though I did address your specifics. This is (obviously) one of my personal peeves. However, as I mentioned, the temperature difference between most parts of a computer when off at room temperature and when running full throtle is relatively small, and the heat is well enough managed that leaving the computer on all the time is completely unnecessary-it will NOT have any positive effect on the longevity of the machine, either on all the time or on/off as needed.