16GB of RAM and still paging out?!?!

iMikeT

macrumors 68020
Original poster
Jul 8, 2006
2,304
1
California
I have a 27" 2011 BTO iMac with 16GB of RAM and I am running OS X Lion 10.7.4. I normally do not need to reboot unless I'm installing updates.

Now since installing Photoshop and Bridge CS6, my iMac is paging out and not freeing up memory when Bridge or Photoshop isn't using it. Someone correct me but isn't 10.7.4 and CS6 designed to better manage memory? And if that's the case, why isn't this memory released back to the system?
 

Intell

macrumors P6
Jan 24, 2010
18,883
373
Inside
Your machine is working correctly. The ram isn't being released because nothing is needing it.
 

leman

macrumors G4
Oct 14, 2008
10,390
4,904
I have a 27" 2011 BTO iMac with 16GB of RAM and I am running OS X Lion 10.7.4. I normally do not need to reboot unless I'm installing updates.

Now since installing Photoshop and Bridge CS6, my iMac is paging out and not freeing up memory when Bridge or Photoshop isn't using it. Someone correct me but isn't 10.7.4 and CS6 designed to better manage memory? And if that's the case, why isn't this memory released back to the system?
Paging out is a normal operation mode of an OS and will likely occur no matter how much RAM you have. Only worry about it if you have lots of paging out. Is your system not fast enough for you, do you experience lag/slowdowns etc.? For all you know, Photoshop may be allocating more memory if it detects more installed memory — I have no idea. But I wouldn't worry about it too much if your computer performs ok and your page outs are on a reasonable ratio. Basically, you want to have much less page outs than page ins. If it holds, than you are ok.
 

Zwhaler

macrumors demi-god
Jun 10, 2006
6,751
1,033
Paging out some is okay. If its less than 1000 page outs there really isn't anything to worry about. Can you use those applications heavily and still have some free RAM? Even if it's only 1GB, thats okay it means your system is utilizing the memory. If you starting having over 3,000 page outs regularly then you are hitting a bottleneck that might affect performance in a small way... 10,000s of page outs per session and you definitely need more RAM.
 

Opspin

macrumors member
Feb 25, 2011
33
0
You need more ram!!!1

I have a 27" 2011 BTO iMac with 16GB of RAM and I am running OS X Lion 10.7.4. I normally do not need to reboot unless I'm installing updates.

Now since installing Photoshop and Bridge CS6, my iMac is paging out and not freeing up memory when Bridge or Photoshop isn't using it. Someone correct me but isn't 10.7.4 and CS6 designed to better manage memory? And if that's the case, why isn't this memory released back to the system?
OMG :eek: you're running dangerously low on RAM! You need 32 Gigs of sweet sweet memory. Interesting fact, you could probably install your entire OS on your RAM if you could figure out how, that would probably make for a pretty swift machine‽
 

chevalier433

macrumors 6502a
Mar 30, 2011
510
13
I have a 27" 2011 BTO iMac with 16GB of RAM and I am running OS X Lion 10.7.4. I normally do not need to reboot unless I'm installing updates.

Now since installing Photoshop and Bridge CS6, my iMac is paging out and not freeing up memory when Bridge or Photoshop isn't using it. Someone correct me but isn't 10.7.4 and CS6 designed to better manage memory? And if that's the case, why isn't this memory released back to the system?
open terminal and write "purge" without the quotes after a photoshop session
 

Intell

macrumors P6
Jan 24, 2010
18,883
373
Inside
open terminal and write "purge" without the quotes after a photoshop session
That command also removed system memory reserves and can slow the system down for a few hours after it is used. It is not recommended to use that command.
 

iMikeT

macrumors 68020
Original poster
Jul 8, 2006
2,304
1
California
Your machine is working correctly. The ram isn't being released because nothing is needing it.
Paging out is a normal operation mode of an OS and will likely occur no matter how much RAM you have. Only worry about it if you have lots of paging out. Is your system not fast enough for you, do you experience lag/slowdowns etc.? For all you know, Photoshop may be allocating more memory if it detects more installed memory — I have no idea. But I wouldn't worry about it too much if your computer performs ok and your page outs are on a reasonable ratio. Basically, you want to have much less page outs than page ins. If it holds, than you are ok.
Paging out some is okay. If its less than 1000 page outs there really isn't anything to worry about. Can you use those applications heavily and still have some free RAM? Even if it's only 1GB, thats okay it means your system is utilizing the memory. If you starting having over 3,000 page outs regularly then you are hitting a bottleneck that might affect performance in a small way... 10,000s of page outs per session and you definitely need more RAM.

Everything is running plenty fast but I just didn't expect to see a machine with 16GB of RAM to ever need to page out. Like I said before, I thought that memory management would be vastly superior in 10.7.x where the system is releasing inactive memory after a task/when quitting an application an not holding it until you reach 0GB free.
 

Intell

macrumors P6
Jan 24, 2010
18,883
373
Inside
The system is not designed to release inactive memory until it is needed. This is done so that if the user reopens a closed program, it can quickly reclaim the already filled and process ram. Rather then reading it from the drive, processing it, and allocating the contents.
 

macbook pro i5

macrumors 65816
May 13, 2011
1,338
1
New Zealand
Everything is running plenty fast but I just didn't expect to see a machine with 16GB of RAM to ever need to page out. Like I said before, I thought that memory management would be vastly superior in 10.7.x where the system is releasing inactive memory after a task/when quitting an application an not holding it until you reach 0GB free.
Look,Its a good thing if RAM is not released because the applications state is cached on to the RAM so if you free up RAM you might actually make it slower

Free RAM=Wasted RAM.
 

iMikeT

macrumors 68020
Original poster
Jul 8, 2006
2,304
1
California
The system is not designed to release inactive memory until it is needed. This is done so that if the user reopens a closed program, it can quickly reclaim the already filled and process ram. Rather then reading it from the drive, processing it, and allocating the contents.
Look,Its a good thing if RAM is not released because the applications state is cached on to the RAM so if you free up RAM you might actually make it slower

Free RAM=Wasted RAM.

Thanks for finally explaining why it's probably good for some things to stay in memory. I'm still a little perplexed why OS X doesn't automatically release the memory once a user quits an application that may not be used for a while so other tasks can take advantage of the free space. Either way, you guys will probably just say that some things should stay in memory (like thumbnails) right?
 

leman

macrumors G4
Oct 14, 2008
10,390
4,904
Everything is running plenty fast but I just didn't expect to see a machine with 16GB of RAM to ever need to page out. Like I said before, I thought that memory management would be vastly superior in 10.7.x where the system is releasing inactive memory after a task/when quitting an application an not holding it until you reach 0GB free.
When it runs well, what do you complain about then? Figures like RAM and CPU usage are first and foremost useful when you have a problem, when you don't have one - they are pointless. Don't try to find an issue where there is none. The memory manager is a very complex piece of software and its inner workings might be not so simple as it may seem to you.

What if I told you that there is practically no way in OS X to really start a new application and the OS does it by cloning existing applications? If you are interested, read up on unix fork(). The kernel will often keep application space or parts of it pre-allocated in order to speed up this process. As someone already pointed out, free RAM is essentially wasted RAM. It is much better spent on caching and other performance-enhancing activities that simply idling there.

----------

I'm still a little perplexed why OS X doesn't automatically release the memory once a user quits an application that may not be used for a while so other tasks can take advantage of the free space.
How do you know that other tasks actually would take advantage of the free space? Maybe they already got all the RAM they need? If they would allocate more, the kernel would surely shift some other-occupied low-priority RAM to them. Its pretty quick anyway.
 

BernardPhoto

macrumors newbie
Jun 8, 2012
13
0
Clearwater
If he's dangerously low than I am in trouble. I've only got 4 gigs of RAM and I work with single PSD greater than the size of my RAM. So big, in fact, that I cannot save them without reducing some of the layers. Photoshop slapped me in the face and said no. No save for you. They are typically composites of 76 or more 21 megapixel tiff files to create a single image. I am holding off as long as I can to upgrade.

OMG :eek: you're running dangerously low on RAM! You need 32 Gigs of sweet sweet memory. Interesting fact, you could probably install your entire OS on your RAM if you could figure out how, that would probably make for a pretty swift machine‽
 

snowydog

macrumors 6502
Aug 25, 2011
315
1
If he's dangerously low than I am in trouble. I've only got 4 gigs of RAM and I work with single PSD greater than the size of my RAM. So big, in fact, that I cannot save them without reducing some of the layers. Photoshop slapped me in the face and said no. No save for you. They are typically composites of 76 or more 21 megapixel tiff files to create a single image. I am holding off as long as I can to upgrade.
I was just searching through the forum for info about Page Outs because my laptop is running slow atm ... anyway - came across your website in your sig and had a look at your portfolio and just wanted to say your photographs are excellent! Really enjoyed having a look through them ... :)
 
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