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Better to sleep or shutdown?

S

strausd

macrumors 68030
Original poster
Jul 11, 2008
2,998
1
Texas
I've heard a few different point of views one this. I've heard its better to shut down because you won't be using energy then and not as much stress on component. I have also heard its better to sleep because of the energy required for boot and when you shut down and start up, the heating and cooling of the components make the contract and expand which will put stress on them.

Power isn't one of my major concern, my major concern is which will make a Mac Pro last longer. With an SSD as the boot drive, it won't need as much power as a mechanical drive so I don't need to worry about that.

Does anyone know which is better? Also, which do you prefer?
 
strausd said:
I've heard a few different point of views one this. I've heard its better to shut down because you won't be using energy then and not as much stress on component. I have also heard its better to sleep because of the energy required for boot and when you shut down and start up, the heating and cooling of the components make the contract and expand which will put stress on them.

Power isn't one of my major concern, my major concern is which will make a Mac Pro last longer. With an SSD as the boot drive, it won't need as much power as a mechanical drive so I don't need to worry about that.

Does anyone know which is better? Also, which do you prefer?
Click to expand...

Option 3 - On 24/7

:D

Before that, I preferred sleeping, so I wouldn't have to wait through the boot process.
 
strausd said:
I've heard a few different point of views one this. I've heard its better to shut down because you won't be using energy then and not as much stress on component. I have also heard its better to sleep because of the energy required for boot and when you shut down and start up, the heating and cooling of the components make the contract and expand which will put stress on them.

Power isn't one of my major concern, my major concern is which will make a Mac Pro last longer. With an SSD as the boot drive, it won't need as much power as a mechanical drive so I don't need to worry about that.

Does anyone know which is better? Also, which do you prefer?
Click to expand...

I never even put my MBP to sleep. It's always on using InsomniaX. Regardless it doesn't really matter what computer it is, just do whatever works best for you. Sleep should be fine. It'll wake up in an instant, but if you aren't going to use it for an extended period of time then shut it down.
 
ZZZZzzzzzzzzzzzzzz......

Mine is set to sleep after 3 hours of inactivity. The screen saver comes on at 25, and the display shuts down after 35. Drives are set in Energy Saver to shut off when not in use UNLESS I am using Logic, then that gets unchecked.

Never had a problem with sleep. Well..... back in the Leopard days sometimes it wouldn't sleep when programmed to (insomnia) but that really hasn't happened w/ Snow Leopard.
 
The general rule back in the day for energy efficiency has been to put the system to sleep, including HDD's/displays/etc. Booting on a daily basis consumes more energy than sleeping the system. Of course this may have changed as systems have become more energy efficient.

As for lasting longer, neither will negatively impact your system. If that's your primary concern, you can do with it as you wish, your hardware will be fine. Booting though may help performance as you typically clear caches and such. Also use maintenance programs such as Onyx or CleanMyMac to maintain system file structure, clean caches and any extraneous software. Hardware wise, you'll be fine.
 
bedifferent said:
Booting though may help performance as you typically clear caches and such.
Click to expand...

It also hurts performance because you have to launch programs from the disk, and no matter how fast your drive is, it's not as fast as already having the program open in RAM.


Furthermore, I've never understood this blind following of the notion that clearing caches improves performance. The entire reason for the existence of the cache is to improve performance. This concept is so fundamental that it's even implemented in hardware. There's a tiny cache on the processor close to the registers (L1). There's an additional cache outside the core (L2). There's often now even a larger cache shared by all the cores (L3). In addition, inactive RAM is used to cache data from the hard drive. Hard drives themselves even have a cache onboard, nowadays. Having your own DNS server reduces latencies because it caches DNS requests. Web browsers can load pages faster if you've already been to them because they don't have to download everything all over again--it's been cached.

The notion that clearing a cache improves performance is completely counterintuitive. It can fix errors if the cache has the wrong information stored in it, but it will also slow things down.

Perfect example: after you install a major OS update (e.g. 10.6.4), it takes a while for the system to boot back up. It even reboots a second time. The reason it takes a while is because the boot cache has been cleared, and it has to be rebuilt.
 
I always shutdown my MP at night, since it's in my bedroom and all. This is more beneficial in the summer when it gets hot in my room, and having the computer on just adds more heat. :)
 
I'm not too worried about it clearing the cache when I shut down because I will have an SSD for my boot drive. I am a little surprised hearing that neither will have a negative effect, but only a little surprised seeing as it is a workstation which is supposed to last.

I think I may shut it down at night and long periods of time without use, other than that I will put it to sleep. I live in Texas and it can get very hot, and it will also be in my room. So I think having it completely off might help keep it a little cooler, however I am not sure how much hotter it will be if its only asleep.

What components are turned on while the computer is asleep?
 
After my last electric bill (more than doubled from previous year) I have decided to shut everything down that is not being used. I even turn off the UPS's at night. But then I have 7 computers and an 8th on the way.

I say shut it down unless you come back to it frequently; then sleep it.
 
Detrius said:
It also hurts performance because you have to launch programs from the disk, and no matter how fast your drive is, it's not as fast as already having the program open in RAM.


Furthermore, I've never understood this blind following of the notion that clearing caches improves performance. The entire reason for the existence of the cache is to improve performance. This concept is so fundamental that it's even implemented in hardware. There's a tiny cache on the processor close to the registers (L1). There's an additional cache outside the core (L2). There's often now even a larger cache shared by all the cores (L3). In addition, inactive RAM is used to cache data from the hard drive. Hard drives themselves even have a cache onboard, nowadays. Having your own DNS server reduces latencies because it caches DNS requests. Web browsers can load pages faster if you've already been to them because they don't have to download everything all over again--it's been cached.

The notion that clearing a cache improves performance is completely counterintuitive. It can fix errors if the cache has the wrong information stored in it, but it will also slow things down.

Perfect example: after you install a major OS update (e.g. 10.6.4), it takes a while for the system to boot back up. It even reboots a second time. The reason it takes a while is because the boot cache has been cleared, and it has to be rebuilt.
Click to expand...

I would agree with you the vast majority of the time. Especially with modern computers. I think it had some merit on old machines, but is now mostly myth.

On older machines that had less ram (remember 64 mb ram chips?) If you cache is full, and you begin to process a large file (large being relative to the amount of free memory) then the OS is going to spend time working to find a free spots in memory to store that cache. And if it can't fit, then it is going to spend time sweeping through the cache looking for the oldest data to delete. If you had cleared the cache before loading the file, then the OS wouldn't have had to do that work.

As for the original question, sleep takes more power than than shutdown.

The wake sequence and the boot sequence take about the same amount of power (most of the same tasks have to happen: loading files to memory, powering graphics, networking, spinning up hdd, etc). Waking only gets to skip the steps that take the longest, but only because those tasks never stopped running.
The difference is that sleep also required power when the system was 'down.'
Off required no power to be 'down'.
On requires the most power all the time.

Personally, I usually sleep when I'm at home and shut it down if I'm leaving for any length of time.
 
When not in use for longer than a couple hours, like when I go to sleep, it gets shut down to stop the injestion of dust. I cleaned it out after six months, and there was only the slightest layer of dust inside. I like that.
 
minifridge1138 said:
I would agree with you the vast majority of the time. Especially with modern computers. I think it had some merit on old machines, but is now mostly myth.

On older machines that had less ram (remember 64 mb ram chips?) If you cache is full, and you begin to process a large file (large being relative to the amount of free memory) then the OS is going to spend time working to find a free spots in memory to store that cache. And if it can't fit, then it is going to spend time sweeping through the cache looking for the oldest data to delete. If you had cleared the cache before loading the file, then the OS wouldn't have had to do that work.
Click to expand...

Yes, thank you. My reasoning was in regards to cache sizes becoming too large for the system to handle. Many average users never clear their browser or system caches. While the premise for a cache is easy accessibility it may also result in errors. It is wise to reset your caches once in a while, especially with system updates.
 
There's really no reason to shut down your Mac Pro unless you won't be around it for a few days. It uses about 6 watts when asleep, which is negligible. Also, all hard drives and fans spin down and the system is completely silent.

I sleep my machine every night and only do a full shutdown when I go on a trip where I'll be away more than a couple of days. And that's more so that my cat can't wake it up by walking across the keyboard, leaving it to be on during the rest of my trip! :)
 
So does anyone know what components are actually being used while the computer is asleep?
 
eemzah said:
According to the Apple tech support, only the RAM is being refreshed every minute. All other parts are powered down. Hope that helps.
Click to expand...

That and if you have "Wake for Ethernet network access" the system will do occasionally tests while asleep. Also check "Put the hard disk(s) to sleep when possible", saves energy but won't do much in terms of HDD longevity.
 
eemzah said:
According to the Apple tech support, only the RAM is being refreshed every minute. All other parts are powered down. Hope that helps.
Click to expand...

So then its pretty much the same as a shut down in terms of components still using energy besides RAM (and the little light that fades in and out)? And how often will someone have RAM fail on them?
 
minifridge1138 said:
I would agree with you the vast majority of the time. Especially with modern computers. I think it had some merit on old machines, but is now mostly myth.

On older machines that had less ram (remember 64 mb ram chips?) If you cache is full, and you begin to process a large file (large being relative to the amount of free memory) then the OS is going to spend time working to find a free spots in memory to store that cache. And if it can't fit, then it is going to spend time sweeping through the cache looking for the oldest data to delete. If you had cleared the cache before loading the file, then the OS wouldn't have had to do that work.
Click to expand...

You just described how normal RAM usage works--not the caches that are on disk being cleared by scripts. You have a bunch of 4k pages. If you open an application or load a file, it must go into RAM, and you either have free RAM or you don't. If you don't, the OS goes through the pages and figures out what data can be freed from RAM. If it can't find anything that can simply be freed, then it must find something old to page to disk which then gets written (very slowly) to disk. This is how virtual memory works. If this is noticeably slowing your system down, you need more RAM. The age of the machine has nothing to do with it, and clearing your caches has nothing to do with it. It's like saying that you should reboot to speed your system up. Sure, it frees RAM--and very unfortunately the disk cache--and might make one thing faster momentarily, but it does so at a bigger cost elsewhere--namely that you no longer have access to that program and file you just closed.

See iOS 4 on the iPhone 3G. The problem is that the device doesn't have enough RAM. Clearing caches won't make it work better.
 
bedifferent said:
Yes, thank you. My reasoning was in regards to cache sizes becoming too large for the system to handle. Many average users never clear their browser or system caches. While the premise for a cache is easy accessibility it may also result in errors. It is wise to reset your caches once in a while, especially with system updates.
Click to expand...

Any properly implemented cache will never result in errors, and it will never get too big to handle. If there are errors, there's either a design issue that users MUST be aware of, or there's a bug. The only example of the first that comes to mind for me is the web browser, but it does not require you to clear your cache. This is what the reload button is for. It's the browsers' way of offering the user a chance to say, "I think your information is out of date." Really, though, requiring the user to be aware of this is a design flaw, and thanks to AJAX, it's not the issue it used to be.

Just because the system clears caches in the background doesn't mean you have to do it too. The system did it because it knew the cache was out of date. You clearing caches that aren't out of date and aren't causing problems just slows things down. If a cache is causing problems, the more important question is: how did it break to begin with?
 
dockingbay94 said:
I never even put my MBP to sleep. It's always on using InsomniaX. Regardless it doesn't really matter what computer it is, just do whatever works best for you. Sleep should be fine. It'll wake up in an instant, but if you aren't going to use it for an extended period of time then shut it down.
Click to expand...

Woah. Hope you let it sleep when you carry it, or that you have very good backups.
 
I have a startup and and shutdown schedule setup for mine.

I have it turn on for a chunk of the working day so that i don't end up watching a load of 'large miscellaneous files' download all evening. (its a habit I picked up from my old ISP which throttled my connection from 4pm-2am)

If I'm not doing that and feeling fruity, I'll set it up to startup 5 or 10 minutes before I get home from work. How about that for lazy/pathetic!
 
So can anyone confirm thats it pretty much the same as shutting down, except for the RAM? And how often will the RAM fail?
 
strausd said:
So can anyone confirm thats it pretty much the same as shutting down, except for the RAM? And how often will the RAM fail?
Click to expand...

It's pretty darn close as far as power consumption goes, but it's not just the RAM. Anything capable of waking up the machine also gets power, so that potentially includes at least USB, bluetooth, ethernet, and Airport.

Any third-party RAM will have a lifetime warranty. This is about the best argument I can give to say that using RAM doesn't cause it to fail. Under optimal usage, the vast majority of electronics don't fail. That is, it's things like power surges (including electro-static discharge) that cause them to fail.
 
Detrius said:
It's pretty darn close as far as power consumption goes, but it's not just the RAM. Anything capable of waking up the machine also gets power, so that potentially includes at least USB, bluetooth, ethernet, and Airport.

Any third-party RAM will have a lifetime warranty. This is about the best argument I can give to say that using RAM doesn't cause it to fail. Under optimal usage, the vast majority of electronics don't fail. That is, it's things like power surges (including electro-static discharge) that cause them to fail.
Click to expand...

So would that mean the logic board gets continuous use even while asleep? Wouldn't that make its life shorter?
 
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