MacBasics: leave your Mac on or shut it down?
Posted by Don Foy 
Mar 24, 2006 at 12:11am
At the risk of starting a holy war, I want to tackle one of the most-asked questions of Mac users across the world: Should you turn your Mac off when you are not using it?
I plan to present both sides of this battle and let you decide on the merits of each argument. I will likely leave out something, so you guys and gals can fight it out in the comments below, but let’s keep it civil. Remember from the last column—we are all family, eh.
So, should you leave your Mac on while you’re at work, or asleep, or asleep at work?
First, the pros. Here’s why you should leave it on, especially at night. Back in the day when Unix boxes were the size of rooms and not everyone had a computer, Unix used what are called cron jobs to “clean up.” Those cron jobs run in the middle of the night when most folks were not using the computer.
Your Mac is now Unix-based, and those cron jobs still run in the middle of the night. The cron jobs are important to keeping your Mac running smoothly.
So you should leave your Mac on so the cron jobs run.
There are other reasons to leave the machine on. And here’s where some of the debate begins. Some say that it’s not the day-to-day use of the moving parts, meaning the hard drive especially, but the starting and stopping.
It also, to a point, doesn’t hurt your Mac to have a bunch of programs running. Again referencing Unix, the Mac “pages” unused programs, while still open, to the hard drive, where the OS can get it back quickly if you begin to use the program again.
And finally, do you really want to wait for the computer to start up?
Now for the other side.
There are many utilities that will run the cron jobs any time you want them run. Or you can even use the command line to edit the cron jobs and change when you want them to run. So there’s no reason to leave the machine on just for the crons.
As far as the wear and tear on the equipment, others say that keeping the hard drive spinning just gets you closer and closer to the day it will fail. And that is not a typo or a misprint. Your hard drive will fail. At least twice in this space have I written about backups. Do them. Before the drive fails and you lose everything.
Some folks also say that if the computer is on during a thunderstorm, you’re more likely to get zapped. I’m not so sure of that, in fact, if the thing is plugged in, you can still get zapped if your surge protector fails (and some would argue that most of them do anyway).
Those are the arguments. Here are my experiences and recommendations as a Mac tech at a newspaper for more than a decade. Your mileage may vary.
At home, I never turn my computers off. They run night and day. I set the hard drives to never spin down. The displays shut off after about 30 minutes, but the machines continue to run.
My Powerbooks are also always on. When I can, they are plugged in, except the old G4/550 PowerBook,whose battery is toast and must stay plugged in. The PowerBooks are, of course, put into sleep mode when the cover closes.
At work, it’s a different story. There, most of the Macs are powered down at night. Of course, servers, which are designed to run constantly, run continuously. Most of my Macs at work have shown now ill effects of being turned on and off each day. They run OS 8.6 and 9 (upgrades are coming in the next few weeks) and we put out the paper each day with them.
So, what should you do? Do what you want. I don’t have any of the newer iMacs with the tiny cases. I don’t have any minis. But aside from some faulty components causing some problems, I haven’t heard bad things about those machines.
Now, play nice in the comments, boys and girls.
hide Says:
I think you forgot one point which could be the biggest.
Reason to turn off your mac for over night.
Turn off so that you would no waste electricity.
Remember? Three Rs!!!
Reduce, Reuse, Recycle!!
Posted on March 24, 2006
Jarod Says:
"At home, I never turn my computers off. They run night and day. I set the hard drives to never spin down. The displays shut off after about 30 minutes, but the machines continue to run.”
That’s my exact setup as well. One of my Macs has been running like that for 6 years straight, only rebooted why software update requires it, never otherwise. They all run great. The biggest electricity consumption comes from the screen so if you’ve set it to shut every 30 minutes, the amount of energy used is minimal at best.
Posted on March 24, 2006
Karen Eliot Says:
Hide is right - what about switching it off for environmental reasons? In the same way as you should really switch off (completely - not just onto standby) your DVD players, etc, etc. It is commonly said here in the UK that if everyone switched off their hifi/tv gear when not in use, we could do without a whole power station.
Posted on March 24, 2006
Rainy Day Says:
Yes, the waste of electricity is the most significant reason to “power down” (i.e. sleep the computer). Global warming is real folks and we have to stop wasting energy. A few million computers powered up doing nothing useful is a terrible waste. Even here in the Pacific Northwest (US) where we enjoy non-greenhouse gas producing hydro-generated electricity, every watt we save is a watt we can send to someplace where power is generated by coal or gas. It all adds up. Even if there were merit (which there isn’t) to the arguments to keep the computer on, the global warming argument would trump them. Fortunately, those arguments are based on myth, misconception and urban legend. I used to work as a computer repair tech, and later as a diagnostic engineer for Apple, so i do know about these issues.
For example, the maintenance (“cron” or “periodic”) scripts are a really lame reason to leave your Mac on. Simply reschedule them to run when your computer is likely to be on, or run them manually. Mostly what they do are clean-up log files, and with the size of today’s hard drives, that’s almost a non-issue. They really aren’t critical to keeping your Mac running “smoothly.”
As for extending the life of the computer by not turning it off, if that was ever true at all, it ceased to be so at least by the mid-1980’s. Your computer will be retired long before the effects of power cycling (if there are any) will ever surface. As evidence, i have a Wallstreet PowerBook that has been in operation since 1998, has always been powered down when i walked away from the computer, and is still going strong today. A high quality surge suppressor (or two) on the line will do far more for extending the life of your computer than anything else.
Regarding electrical storms, no surge protector can prevent damage in the event of a nearby direct power-line hit. I always unplug my computers (and any attached cables) during an electrical storm, even though i use high quality surge protectors. By the way, all surge protectors degrade over time. When a surge occurs, the devices clamp the spike but the process either destroys or degrades the component (depending on the amount of energy in the spike). There are little micro-surges in almost every environment which occur all the time, caused by such things as a nearby electrical motor starting up, etc.
While hard disks are the most likely point of failure, their reliability has improved a lot over the years. I’ve never lost data due to a fixed-head hard drive failure… but i have had some drive bearings start to get noisy and annoy me to the point i replaced them. Some would argue the noise meant the drive was about to fail. While it is true a noisy drive is probably closure to failure than a quiet drive, noisy bearings do not necessarily mean drive failure is imminent (nor do all drives become noisy prior to failure).
Posted on March 24, 2006
Rainy Day Says:
Jarod - Even the processor takes quite a bit of power. There is no reason to just leave it idling.
Posted on March 24, 2006
Jarod Says:
I suppose you guys are right. alright, you win :-)
Off they go in the evenings. I’ve set them all to shut down automatically at 1am and reboot at 8am when i need them.
Posted on March 24, 2006
Anndra Says:
You can set the hard drives to sleep, so you don’t wear them out as fast. The waste of electricity is a good argument, but my machines run the folding@home client. I think it’s a waste of powerful expensive computing power to have it sitting idle, let it do some good.
Posted on March 24, 2006
Ivor Says:
Love the attitude.
No wonder the world is going to hell in a handbasket when some people won’t simply turn their computers off at night because they think it will improve the performance of their Apples. Or for any computers for that matter.
There are bigger things at stake than how many times those dock icons bounce up and down before opening your apps. If you are not using your desktop/laptop at night...shut it down. Would you keep your TV on all night if it kept a clearer picture?
Posted on March 24, 2006
Sprocket999 Says:
Yes, I tend to agree somewhat on the hydro wastage issue as a result of leaving the gear on all night. These aren’t servers. They don’t do preset series of tasks in sequence, so my equipment shuts down at night. My opinion is that the hardware benefits from a ‘reset rest’ periodically. That said, I do know some who will shut the gear off if they go out to a meeting. I don’t. Tinker with the energy settings so it will screen-down after 30 minutes (with password on if in a work zone) and head out. The gear stays on all day. If there are behind the scenes cron tasks to run, they can do it then. Normally, though, I run utilities periodlically to do this.
I’m a firm believer in UPS units for the business world. I consider it very cheap insurance. I also recognize there are a lot of dodgy UPS units out there. Personally, I have had very good results with APC over a decade. And I use one that is somewhat-overrated for my setup at home, I replace the unit about every two years, as we do get some wicked thunderstorms here and commonly fluctuating power supplies. At work management doesn’t understand any of this. I’m lucky they even agreed to UPS units for us in the first place after years of my lobbying. it finally took (how did you NOT see this coming) a major hit on one of our production Macs to loose almost a days worth of critical work for them to understand the impact—not to mention the hardware replacement downtime involved. I agree with ‘Rainy Day’ that UPS units ALL do eventually break down from taking the hit so many times for your equipment, and not understanding that can put you in an exposed position. Not good at all.
Posted on March 24, 2006
Mike G Says:
In 10.4 the cron jobs have been changed so that they run overnight (as before) or, if your computer is off when it is scheduled to run, they run the first time your computer is on with 15 minutes of inactivity. So that argument to leaving your computer on is a non-point with 10.4.
I still leave my computers on, with my monitors set to sleep after 20 minutes of inactivity.
Posted on March 24, 2006
Mantis Says:
"At home, I never turn my computers off. They run night and day. I set the hard drives to never spin down. The displays shut off after about 30 minutes, but the machines continue to run.”
Ever heard of power saving?
I can understand the debate about shut down VS sleep, because the difference in power consumption is minimal. But having the computer run all night is just plain ridiculous!
Kyoto protocol anyone? Oh well…
Posted on March 24, 2006
Chad Says:
We leave ours on day and night and have found that our power bill has dropped considerably. We had to get a new power supply in our imac G5 and the genius that worked on it told us to leave it running and see if our power bill was affected. It was!!
Chad
HUD Home
Posted on March 24, 2006
Alice Says:
Leave it on. I’ve never turned a Mac off and have never had a machine go south. My husband and son, on the other hand, always turn theirs off at night and every one of them has had a major hardware failure.
Posted on March 24, 2006
Karen Eliot Says:
Chad - are you somehow arguing that leaving your computer on all the time saves electricity? This seems… somehow unlikely.
Alice - I switch my computer on and off all the time. I’ve never had a major system failure. I’m not saying you’re wrong or right - just that that is my experience.
Posted on March 24, 2006
Scott Schuckert Says:
The document has been off-line for a long time, but the Apple Tech Info Library once addressed this. The recommendation was to turn your computer on the first time you needed it that day, and leave it on UNLESS it was going to be off for more than 8 hours.
This was supposedly the best compromise between energy usage, equipment wear, and convenience.
Posted on March 24, 2006
BlueMeanie Says:
i agree with the points in this article, but along with the initial ‘jerk’ of the disk heads as they rise from the platter and sit upon their little air pockets… i also consider the issue of thermal expansion (heating/cooling) of components to be of critical note when frequently shutting down.... the difference in the thermal expansion coefficients of the different materials in a computer must have impact over time…
i normally relate it to a light bulb… when do light bulbs normally fail? you turn the switch and pop… of course that’s not to say a light bulb doesn’t have a finite “on” life....
Posted on March 24, 2006
fluk3 Says:
Leave your computer running.
Saving a few watts won’t stop the Sun from enveloping the Earth one day. Global warming, if real, is irrelevant. The planet is inevitably doomed in time. We all know it.
It’s like telling the Titanic to conserve coal.
Use your macs while you can. Make the most of it.
Perhaps someday we’ll have a better source of energy and conservationists will be a relic of the past. Until then, don’t mind the hippies.
If you really want to save energy, lobby to have all the street lights extinguished or turn off all the surveillance cameras. That’s a much bigger waste of energy. Not to mention light polution and privacy vilolations.
Or maybe shut down the airline industry. Travel is frivolous anyway. Much more-so than me leaving my mac running all night so I can recored my PVR TV shows.
Posted on March 24, 2006
Hilmar Says:
I agree with the previous posters, what about saving energy?
And there is no need to turn the computer off to do that, you just need to put it to sleep when you aren’t using it.
The power consumption on my powermac when in sleepmode is almost exactly the same as when it is turned off completely.
I don’t turn off my computer since it takes almost a minute to boot and log in to mac os but since it wakes up from sleep almost instantly I personally see no reason not to use the sleepmode.
Posted on March 24, 2006
ken2 Says:
I put the PB in the office to sleep at night, but the G5 iMac at home is on all the time. I ran into the Folding@Home project from Stanford University (http://folding.stanford.edu/) and felt it was worth the cost of the electricity to let the iMac do a bit of medical research.
Posted on March 24, 2006
Tom Says:
I read a few years ago that most computers consume about 6 watts of power in sleep mode and 8 watts of power running.
If you really want to save power then unplug that computer also.
Posted on March 24, 2006
Tracy Valleau Says:
Mac Quad: 1 watt p/h off; 17 wph sleeping. In one year, that’s either 2900 watts (off) or 74,000 (!) watts sleeping.
I actually asked a Maxtor tech rep about leaving hard drives on vs turning then on and off. Reply:” both are within spec; it makes no practical difference.”
Finally, turning off at night forces a restart and hence reset of everything once a day. Not sure that makes much of a difference, but it certainly can’t help. Even my server has an option for restart periodically.
My choice (after running computers 14 hours a day, every day, since 1978): off at night.
Posted on March 24, 2006
hide Says:
I didn’t expect so many people agree with me.
For Tom.
I don’t know where you read it but I found a web about power consumptions, and according to this, more than 100w for idle, ,less than 10w for sleep.
As for unpluging computers, computers have battery inside for maintain, time and other things when it’s unpluged. So if you keep unpluging, then you will kill the battery. I wouldnt suggest unpluging computers.
Posted on March 24, 2006
ncm Says:
I sleep my G4 MDD at night (Macaroni takes care of the cron tasks), and set the displays to sleep after about 30 minutes...unless I’m doing a long backup or something else that needs me to see what is going on. I seldom turn it off - just when I’m away for at least a couple of days or when doing maintenance like cleaning the dust balls out of the box or installing hw inside. I’m not using this Mac as a server so there is no need to keep it up 24h a day. The G4 PowerBook is usually sleeping with the lid closed if I’m not using it. Tend to keep it plugged in at home. I turn it off while travelling, and power up if I want to use it on a plane or train.
I don’t see much point in not sleeping a desktop Mac at night unless it is being used as a server.
Posted on March 24, 2006
Tony Says:
Fluk3 writes “Or maybe shut down the airline industry. Travel is frivolous anyway.” Right, like that’s rational bonehead. You must live in a hole in the desert to come up with that one. The heat is getting to your brain. Maybe shut it off (your little brain ) to save energy.
:-)
Posted on March 24, 2006
macnews Says:
Not taking sides either way, just explaining how start-ups can take more electricity. Most electrical components take the most power when the start up. If you start up and shut down a lot, it could theoretically take more power than just leaving the computer running. I suspect it would take significantly more than just once a day startup/shut down, but depending on the age of your machine and the components inside, it could be possible.
Posted on March 24, 2006
ncm Says:
ps. I recently had a scare when my G4 MDD started overheating. Fans are mechanical and they wear out too. In this case an internal/external cleaning helped and though I’m keeping my eye on Temperature Monitor, the Mac hasn’t overheated since. But sleeping it at night will cool it down somewhat and help keep the fans working longer...something essential for this “wind tunnel” model (gg).
Posted on March 24, 2006
NSN Says:
I guess we should just leave our cars running all of the time..you know, all of that starting if we shut it off will kill the engine. And also, the amount of gas it takes to start the car must be more than leaving it running over night…
right…
Let’s stop using those arguments.
Posted on March 24, 2006
BZ Says:
Put your Mac to sleep or turn it off. Please don’t leave your Mac running overnight just to run 10 minutes of cron jobs.
You would think in this day of depleting energy, people would be a bit smarter about these types of things.
BZ
Posted on March 24, 2006
Chad Says:
Yes, we actually saw a DECREASE in our power comsumption for the month that we started leaving our mac on. The genius at our Apple store told us that the actual act of starting up the mac from a turned off state takes up A LOT of electricity and power. So, we’ve seen the results!
Chad
HUD Homes
Posted on March 24, 2006
George Lien Says:
Found an error between “PowerBook” and “whose.”
“My Powerbooks are also always on. When I can, they are plugged in, except the old G4/550 PowerBook,whose battery is toast and must stay plugged in.”
You need a space after the comma.
Best Regards,
George Lien
Posted on March 24, 2006
Tony Says:
George, you need some space between your ears.
Posted on March 24, 2006
Buck DelFuego Says:
I agree with the energy conservation crowd. I see no reason to leave my iMac on at night, needlessly draining power. I certainly don’t dote over the machine, and I must admit I didn’t even know OS X ran cron jobs at night. Regardless, I’ve had the computer for over 4 years, and other than a failed stick of RAM, I’ve had no problems with it. It runs as well as the first day I bought it. Actually better, since I upgraded to 10.4.
I’m skeptical of the claim that the computer uses more energy turning on and off than just staying on all the time. I don’t see how 1-2 minutes of booting up and down can possibly use more energy than 8+ hours of continuous operation.
Posted on March 24, 2006
gr Says:
Thanks, Chad! Absolutely right; it costs less and uses less power to run them 24/7.
You others comparing the way a computer works and your cars . . . do I need to say it? That’s a fallacious comparison and you’d know it if you thought about it.
Posted on March 24, 2006
NoDice Says:
Well—with so many people leaving their macs on at night I can see why this country is always suffering power shortages. It all adds up, you know. I hope none of you are in California.
Posted on March 24, 2006
gr Says:
"Would you keep your TV on all night if it kept a clearer picture?”
Of course not. Dumb analogy.
But if it increased the life expectancy of the TV AND cost me (and the planet) less every month? Duh!
I manage 100+ Macs for a department in a university that is VERY concerned about budgets and cutting costs. And yet they encourage me to leave them all on all the time . . . wonder why? Trust me, they have no interest in saving me or my clients time or effort. They’re interested in the bottom line.
It’s simple: their bean counters have run the numbers and taken into account electricity bills, repair costs, upgrades, etc. and proclaimed that the school saves a lot by leaving machines running.
OFF=no cost/power & ON=lots of cost/power works for your toaster. So I would recommend turning your toaster off when you’re not using it. But trying to extend that logic to your computer? If you can’t compare Apples to oranges, you certainly can’t compare them to toasters (or cars or TVs or . . . .)
Posted on March 24, 2006
TinkerBox Says:
Ever notice how many TVs and Stereo units are on ‘standby’ after you punch the ‘off’ button? From what I’ve seen—they all are. And these ‘voltage vampires’ are doing the same thing as your Mac left on all night (except running crons that is) which is sucking a steady stream of juice which is supposedly lessening the wear and tear of the hardware at start-up time by not using the BIG GULP of electricity to power up. I find this type of technology irresponsible and so ‘80s in mindset.
Posted on March 24, 2006
What's the frequency, Kenneth? Says:
Get a KVM, which you should have anyway, and deep sleep it. Unless you lose power for a LONG time, should be no worries.
Posted on March 24, 2006
What's the frequency, Kenneth? Says:
I said KVM--don’t know why--I meant UPS (uninterruptable power supply.) That will help protect you from both electrical failures and surges--usually.
Posted on March 24, 2006
JR565 Says:
Anyone leave their clock radios on at home when they’re not around or when they leave for work?
You selfish bastards! Don’t you realize the power you’re consuming?!
Probably more than a power mac in sleep mode, I think.
Posted on March 24, 2006
Joe Says:
My Dual G5 uses about 200 watts of power while running. If starting up the machine used more power than the total consumed by running it for 8 hours, I’d blow a circuit breaker every time it started up. The notion that letting it run continuously uses LESS power is sheer idiocy. Sorry, but “I checked my power bill!” doesn’t cut it. Someone would have to provide some actual power consumption figures to explain how this miracle is possible. What do computers do, smelt aluminum for 10 minutes while they start up?
Posted on March 25, 2006
nikes Says:
Probably more than a power mac in sleep mode, I think.
Posted on March 25, 2006
JR565 Says:
How about tradeoffs though? For example, people who live in studio apartments consume far less electricity than those living in a huge house. Likewise people who crank the air conditioner in the summer (sometimes when they sleep even) consume a ton of electricity. If we don’t use the air conditioner or live in a small place how’s about letting us not turn off our laptops, whereas, how about if you have a big house and have air conditioning for a whole household you ration your computer use to once a week.
Posted on March 25, 2006
insomniac Says:
I leave my computers on 24/7 as I can’t bear waiting for them to boot up. Too many electrical gadgets in use also like DECT phones, airport base stations, electric toothbrush, iPod dock, digital clocks, routers, microwave (for the quick fix) - doesn’t help with the energy use I know. I wish I could do something but I’m just an impatient insomniac…
Posted on March 25, 2006
He Says:
Powerbook, I leave it on all the time. Goes to sleep after twenty minutes of inactivity. Turns 3 years old in a month. Still like new.
Mac mini, I leave it on all the time. Whenever I am finished using it, I go to the Apple icon on the upper left corner, and select “Sleep”. Everytime.
After reading the above discussion, I will keep doing what I’ve been doing. I believe that shutting it down 1) requires a boot that consumes more watts than if I let it sleep overnight 2) damages the hard drive more than waking it up.
Sleep, my trustworthy babies. I know you’ll be ready for another long day tomorrow.
Posted on March 25, 2006
nomad Says:
Some of these ideas are ridiculous.
You saved on your power bill and you attribute this to leaving your computer on? Do you not have any other electrical appliances? Puh-leeze.
And for those of you who are relying on anecdotes to suggest that doing one or the other conclusively shows that it’s better for the computer’s longevity: go take a course on science; any science; seriously. The fact that your son or husband or dog or cat had a particular experience with his/her/its computer after doing a particular thing doesn’t show cause and effect, just co-incidence.
For the original poster of the article: how is this even a story?? I’m going to introduce a topic; refuse to draw a conclusion and intentionally incite a flamewar. I remember why I stopped reading this site.
Finally, for what it’s worth, I use a powerbook G4 - it isn’t as good as new; i’ve upgraded the ram and added an airport card; the hard drive has failed and been replaced (after a nasty fall: what i wouldn’t have done for that shiny new motion sensor) and the powercord has been replaced. That said, it does it’s job. It’s about 5 yrs old - I put it to sleep at nights, though after considering the power consumption issue, I will be turning it off.
Thank goodness for the majority of users in this forum, because it’s the only thing worth reading on the site ;p
Posted on March 25, 2006
AppleGirl Says:
All of you sound like idiots. PEOPLE PAY THEIR MONEY AND THEIR ELECTRIC BILLS THEY CAN DO WHATEVER THE HECK THEY WANT.
Posted on March 25, 2006
AppleGirl Says:
All of you sound like idiots. PEOPLE PAY THEIR MONEY FOR THEIR COMPUTERS AND THEIR ELECTRIC BILLS THEY CAN DO WHATEVER THE HECK THEY WANT.
Posted on March 25, 2006
Jesse Says:
First, I’d like to say it’s the users choice to leave it on or off.
Now, the power your computer uses while in sleep mode all night is less than or about the same as how much it takes to start it up. There is no big difference really, but if you believe that your computer will last longer by not turning it off and on all the time(I am one of those people), then who cares? Keeping your computer in sleep mood uses less power than keeping a light on all night.
Posted on March 25, 2006
Daniel Says:
I used to leave my computers on all the time, just easier for when a task came on (I run a small network at home, various clients; and midnight printing jobs aren’t that uncommon), so my Mac Mini always stays on. My PB 15” used to always stay on, but now not so much as I’m living elsewhere and my power has a tendency to shutoff randomly - not the best thing when I need it for a full day the next day, so Standby with a simple lid close.
Posted on March 25, 2006
Moctod Says:
By off do we mean ‘off’, or can it mean ‘sleep’?
At the end of the day I put myself to sleep. I figure having to re-boot myself - if that were possible - would be highly inefficient, ;-) and it most certainly would be cost prohibitive.
BTW, ‘who’ would be willing to ‘insure’ that I would ‘boot’ tomorrow morning?
FWIW, the amount of energy - or calories, as we humans normally phrase it - that we use when we sleep is absolutely LESS thAn the amount of calories we use than when we stay awake 24/7. But, having to use a Defibrillator every morning may actually be stressful on the parts of our hardware package.
There are always compromises in ‘life’.
Should we drive eight miles out of our way to get gas 2¢ cheaper, to fill our full-size, penis-enhancing SUVs that hold one passeanger 95% of the time? Should we fill a central landfill with a thousand extra plastic shopping bags (reusable, btw), or cut down one hundred extra oxygen-producing trees to make enviro-friendly paper shopping sacks?
If leaving my iMac in sleep at night means I get one extra year of use before MTBF, then I’ve ultimitely lowered my TCO, no? I’ve lowered my Total Cost of Living, thus lowering my total need for resources.
Being alive - by definition - means you WILL use some resources. Calculate where you actually get the most for the least. But, don’t use too much time. Sometimes failure teaches us quicker!
Posted on March 25, 2006
Martin Says:
Saving energy is the point here, coming from germany it’s sometimes pretty tough to see how energy is wasted in the good old US. We do not all drive big V8s but small hi-tech diesels because of energy saving, and when you consider, that only in little germany all the energy that could be saved alone from electrical hardware running in standbymode is enough to shut down one nuclear-powerplant.
So maybe you could shut-down one powerplant alone frome switching off useless running mac!
Cheers
Posted on March 26, 2006
Brett Patterson Says:
Don’t forget too the people who are running a small fileserver or messaging system or data backup plan (over both local and remote networks) that requires occasional but all-hours access. This sort of stuff is going to become more common, not just for high-end users, to the point where turning off your computer rather than using a good (low-power usage) sleep mode would seem as unusual as unplugging your fridge every day when you go to work.
Even if a computer in a home or home-business situation wouldn’t be constantly busy, it will increasingly need the ability to wake up several times a day for essential tasks (scheduled backups, ‘alarm clock’ programs that wake you up with music in the morning, etc).
Posted on March 26, 2006
Just the facts, pls... Says:
Having worked in the electronic repair industry, the initial “power on” cycle is potentially the most dangerous for your hardware. This is because the filter capacitors in the power supply are not fully charged and potentially allow power spikes. How many times have you had an electronic device fail when you just start up vs it failing while it had been on? All capacitors eventually deteriorate and multiple power on cycles tend to accelerate the MTF. From the point of protecting your equipment your better off leaving it running than doing 3-4 power cycles a day. Which uses more electricity can only be determined with proper testing. It is a fact devices tend to use more power on initial start up versus their steady “on” state. Motors draw the most amount of current at startup and power supplies take more momentarily as the capacitors fully charge up. But is it more that leaving the system on 7/24? Only careful measurements will say for sure.
Posted on March 26, 2006
headwerkn Says:
our work Macs have to stay on during the dark hours ‘cause that’s when they back themselves up to our server via DejaVu. otherwise my systems all get put to sleep (unless they’re busy with bittorrent), but more so to save LCDs and cut noise than save power.
but really, each to their own. i figure it is all about balance.. like that person said, i don’t have an air conditioner, so i can run my system 24/7. it’s like how because i don’t own a pool nor have lots of annoying kids, i can have long, hot, water-wasting showers. so ya boo sucks… :-p
Posted on March 26, 2006
cfranz Says:
hmmm. interesting. of course, it’s everyone’s own choice what to do with their macs. if you want to keep it on overnigh, go head. but please do not try to justify your actions with silly arguments.
macs have various modes of energy consumption. my G5 draws in excess of 200W when fully loaded on a hot day (this includes power required to drive other hardware). In sleep mode, this amount is reduced, but certainly not zero. Some people say that the amount of power drawn during sleep is the same amount that would be used during the power-up cycle. This may be true if the sleep cycle is short enough, but not after a few hours.
Turning the mac off when not in use is environmentally-wise probably the best choice (something, it appears, woefully few US-living people can relate to). The statement that their G5 draw less energy turned on 24/7 than being shut down for 8 hours a day is so silly it doesn’t merit a response - just think about what joe said: what would happen if your mac blew 200W*8h = 1.6KWh during startup? More than it’s circuits. May I strongly recommend you attend some basic schooling before relating stories like that in the future?
So, put them to sleep, leave them full on, or turn them off as you please. If you leave them on, aknowledge that you waste energy, but feel that you get something else in return you think is worth your while.
-ch
Posted on March 27, 2006
Rainy Day Says:
To save power on a Mac, simply use sleep mode; no need to do a “shut down” at night. On a Mac, sleep mode is very power efficient (not the case in the Windoze world, btw) and the difference between sleep and power-off is very, very small. So set your computer to sleep automatically after a period of inactivity, and use the sleep command when you know you’re going away from the computer for more than just a few minutes. Your planet will thank you.
The notion that powering up the computer takes more power than allowing it to run 24/7 is ill-informed and based on partial truths.
For example: Yes, motors draw the most power when they start up, but this is very brief (and the motors in disk drives and fans are very small and pretty efficient). The extra power draw to spin these up in a computer is infinitesimal compared to their normal operating requirements over even a moderately short period of time. In other words, the extra power required to start up one of these motors is equivalent to spinning it another second or two at best.
As for capacitors in the power supply drawing more power on a cold start: All modern Mac’s have a fully operating power supply even when the Mac is fully “powered off.” The power button is actually electronically controlled, and thus requires power! (This is why many Mac models won’t power up if the PRAM battery dies, btw.) This is also how your Mac can have a System Preference setting to “Restart automatically after a power failure.” There is always a trickle of power being supplied to the logic board for maintaining clock and PRAM, and charging the onboard PRAM battery. So this power supply capacitor argument simply is not valid (because the power supply is always operating anyhow, albeit in a low power mode).
The energy saved by not running your computer 24/7 may not compare to the energy wasted by flying a jet, but it all adds up and all contributes to global warming. In as much as there are hundreds (or thousands) of millions of computers in the world, this is no small number.
Don’t be a pinhead; use sleep mode! You’ve nothing to lose.
Posted on March 27, 2006
cfranz Says:
BTW, just for the sake of this argument: Apple’s web site (can’t check the docs from my Macs now), on their enviromental pages, offer a calculator how much you save using energy saver. From a quick glance (certainly no scientific analysis) it appears that using the energy saver feature in a Mac reduces energy consumption by 50% (setting: 7 days with 12 hours per day workload). Putting the Mac to sleep can’t therefore save much more than 50%. Sleeping your Mac appears to be much less an energy saver than I initially thought. Turning it off will of course reduce energy consumption to close to zero (unplugging it will bring it down to zero - if you disconnect the internal battery).
-ch
-ch
Posted on March 27, 2006
ebow Says:
Nothing new to read here, move along…
The information provided was nothing beyond the anecdotal arguments I’ve read in several Mac forum threads. And the main story even failed to mention Sleep as an alternative for what to do when you’re not using the computer. I was hoping for an authoritative breakdown of MTBF (mean time before failure) of hardware components for shutdown vs. always on (vs. sleep) and power consumption levels for some of the more popular Macs across the three power choices. If those figures aren’t available from manufacturers, then perhaps some lab should run some tests. Then you’d have something to talk about.
All you’ve done is start the same tired debate in a new location.
Posted on March 27, 2006
Rainy Day Says:
cfranz sez: “using the energy saver feature in a Mac reduces energy consumption by 50% (setting: 7 days with 12 hours per day workload). Putting the Mac to sleep can’t therefore save much more than 50%. Sleeping your Mac appears to be much less an energy saver than I initially thought.”
Think about what you’re saying: If using energy saver (i.e. sleep mode) saves 50% while your Mac is sleeping 50% of the time, then sleep mode saves close to 100% while it’s sleeping!
I looked up the energy calculator page. If you tell the calculator that you want to sleep your computer all but 2 hours a week, it says you save 98%, which implies that sleep mode uses less than 2% the normal operating energy. There appears to be some rounding error on the page, however, so it’s hard to say for sure exactly how efficient sleep mode is.
So if you turned the computer completely off for 8-hours at night, the most you could save, verses sleeping the computer during that time, is a third of the sleep mode current, which doesn’t appear to be a very large number.
Posted on March 27, 2006
cfranz Says:
Indeed - I stand corrected. How silly of me to completely blow a simple calculation just after calling someone else unscientific. I guess I deserved that. Thank you Rainy Day for setting me straight.
On the upside (for me), it’s good to see that sleep mode does appear to have a real, positive effect.
-ch
Posted on March 28, 2006
Dale Meyn Says:
Hard drives are the components most likely to suffer from on/off cycles, probably. Most are designed to withstand 50,000 “landings” with a 50% failure rate, i.e., letting the read head come down on the platter as it spins down. This comes to 13.7 years at 10 on/off cycles per day. In other words, after 13.7 years of 10 hard drive on/off cycles per day, there is a 50% chance the read head will start acting up. Most HDs are retired after a few years, or fail from other causes. But, no doubt it is best to avoid shutting down your HD more than once a day, so set the “energy saver” panel or whatever PCs use to leave the HD running thru sleep during the day, and just shut down the computer (and HD) at night. That would save a lot of wear and tear on the drive mechanism. As someone pointed out, even when shut down, computers keep some small amount of power going to enable it to start up readily, and it’s really a very small amount, less than an LCD clock display, probably. As for cars, didn’t you know that a small amount of power is used when they’re off to keep various electronic gizmos alive, such as the clock and other electronic components? Let’s not resort to sarcasm and name-calling to quell opposing viewpoints. Dale Meyn
Posted on March 30, 2006
arsea Says:
Regarding the newer iMacs, you said, “aside from some faulty components causing some problems, I haven’t heard bad things about those machines.” Please tell me what could be worse than “faulty components.” My G5 iMac failed after only nine months, causing signficant inconvenience and data loss. This is so commonplace that I didn’t even need the warranty for the $1300 in repairs. If Apple is making such shoddy equipment now, it surely won’t matter whether the machines are left on or off.
Posted on April 05, 2006
dev Says:
Randy Farber (head or applecare) told me personally that newer macs use 3w sleeping and 5w when “turned off”. So they actually use LESS ELECTRICITY when turned sleeping!
I had some documentation but can’t seem to find it now. It’s true!
Posted on April 12, 2006
Art (MacGig.com) Says:
One Con comes to mind…
the cost of electric. I’ve read that leaving a computer on all year adds around $70 to your electric bill. Seems like wasted money to me.
Posted on June 02, 2006
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Don Foy
Don Foy is a past president and current Apple ambassador for the Upper Cumberland Macintosh User Group in Cookeville, Tennessee. He is also a former newspaper reporter who has been fixing Macs for 13 years. His first Mac was a Mac Plus maxed out with 4MB of RAM and a 17MB hard drive.
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dbc Says:
Leave it up. On a UPS. And then tell those twits at Apple to either make their clean up jobs compatible with cron so that they actually run, or else fix launchd so that it actually works as advertised. cron and lauchd are flat out b0rked, and *that* is the crime you should be writing about, not trying to start a foolish flamewar among users about whether or not they should shut down. Users should do what works for them.
Posted on March 24, 2006