Q: Lion - Memory Usage Problems
-
Jul 28, 2011 7:30 AMby R C-R,Even if you don't launch any apps there are quite a few processes that the OS runs in system space -- in fact, just logging into your account starts up quite a few processes in user space. Most processes are "faceless" -- they have no user interface -- so you may not be aware of them.
Also, the memory manager does not release previously used memory to the free space pool until there is a reason to do so. Typically, quitting a process won't release all the memory it used, in part because some of it is shared with other processes, & in part because some other processes may be able to use some of it. How the memory manager works is not easy to understand (see the previously mentioned developer document if you want to tackle that subject) but it isn't so simple that just looking at free memory will tell you if you have a memory leak or not.
As several have mentioned, the most useful number Activity Monitor gives you is the page outs. Lion actually gives you two numbers. The first is the cumulative amount of memory paged out since the last startup; the second is the recent rate at which memory is being paged out to disk. If these numbers (especially the second) suddenly start increasing it means the memory manager has run out of real (physical) memory for the running processes & your Mac will slow down while the data has to be paged out to the disk. (Page ins are not as serious because much of what is paged in can be discarded without having to be paged back out to the disk.)
Brief, occasional page outs don't have much impact on performance but if they occur repeatedly lead to "disk thrashing" -- constant disk activity when you try to do almost anything. This is accompanied by frequent appearance of the spinning "beach ball" cursor, the OS's way of telling you that you must wait for it to finish doing something before it can process your request.
If you see no slowdowns or frequent beach balls, you almost certainly don't have memory issues.
-
Jul 28, 2011 7:36 AMby mightymilk,ColoradoiPodUser wrote:
This morning, after leaving my Macbook run all night with no apps launch I come to a machine with only a couple hundred MB of free memory.
Is this not a memory leak? I have the same thing happen after a day of normal use (with several apps running).
Now the system doesn't seem to be especial slow, but I was told a while ago by a "Genus" at an apple store when available memory gets low I should reboot.
Is Lion just managing memory much differently from OS X 10.6.??
Enough information has been provided that's it's clear we either have a leak, or there's a serious mismanagement of memory going on. Compare your Windows/Linux machine at home your Mac, and you'll find they aren't using anywhere near the same amount of resources, even if they're running the exact same tasks. Leave it running all day and watch as OS X eats up all available RAM, while Windows and Linux have no trouble acquiring and releasing RAM.
There's a reason the general consensus has always been:
If all you need to do is check your mail and surf the web, then you don't need the latest technology.
Those tasks are not intended to draw heavy consumption from the system. This is common knowledge, and that's what makes people arguing to the contrary so laughable.
-
Jul 28, 2011 7:37 AMby John Kitchen,R C-R wrote:
<snip>
As several have mentioned, the most useful number Activity Monitor gives you is the page outs. Lion actually gives you two numbers. The first is the cumulative amount of memory paged out since the last startup; the second is the recent rate at which memory is being paged out to disk. <snip>
Great posts, thanks!
I had assumed that the rate of page out was averaged since the last boot, but if it's a recent average, then it's a whole lot more useful!
Question. Do you know how they define "recent" or how it's calculated?
-
Jul 28, 2011 7:39 AMby mightymilk,R C-R wrote:
Even if you don't launch any apps there are quite a few processes that the OS runs in system space -- in fact, just logging into your account starts up quite a few processes in user space. Most processes are "faceless" -- they have no user interface -- so you may not be aware of them.
Also, the memory manager does not release previously used memory to the free space pool until there is a reason to do so. Typically, quitting a process won't release all the memory it used, in part because some of it is shared with other processes, & in part because some other processes may be able to use some of it. How the memory manager works is not easy to understand (see the previously mentioned developer document if you want to tackle that subject) but it isn't so simple that just looking at free memory will tell you if you have a memory leak or not.
As several have mentioned, the most useful number Activity Monitor gives you is the page outs. Lion actually gives you two numbers. The first is the cumulative amount of memory paged out since the last startup; the second is the recent rate at which memory is being paged out to disk. If these numbers (especially the second) suddenly start increasing it means the memory manager has run out of real (physical) memory for the running processes & your Mac will slow down while the data has to be paged out to the disk. (Page ins are not as serious because much of what is paged in can be discarded without having to be paged back out to the disk.)
Brief, occasional page outs don't have much impact on performance but if they occur repeatedly lead to "disk thrashing" -- constant disk activity when you try to do almost anything. This is accompanied by frequent appearance of the spinning "beach ball" cursor, the OS's way of telling you that you must wait for it to finish doing something before it can process your request.
If you see no slowdowns or frequent beach balls, you almost certainly don't have memory issues.
Most of us are having performance issues. That's been mentioned quite a few times.
Maybe you should read the thread.
-
Jul 28, 2011 8:16 AMby R C-R,mightymilk wrote:
Most of us are having performance issues. That's been mentioned quite a few times.
Maybe you should read the thread.
I have read the thread quite carefully.
Maybe you should do the same because the points you seem to be missing are that a) not everyone is reporting performance issues -- many are just expressing concern about the numbers Activity Monitor reports & make no mention at all of any specific performance problems, b) few reports contain enough details to tell if there really is a memory use issue, & c) these issues have several different causes, not all of which are directly related to memory use.
Basically, you are assuming that a lot of users have exactly the same problem you do & it has exactly the same cause. It remains to be seen if that is a good assumption or not.
-
Jul 28, 2011 8:21 AMby R C-R,mightymilk wrote:
Compare your Windows/Linux machine at home your Mac, and you'll find they aren't using anywhere near the same amount of resources, even if they're running the exact same tasks.
No two different OS's ever run "the exact same tasks." If they did, they would be the exact same OS.
Earlier you said you were not trying to insult anyone's intelligence, but you seem to be doing a fairly good job of that now.
-
Jul 28, 2011 8:25 AMby mightymilk,R C-R wrote:
mightymilk wrote:
Most of us are having performance issues. That's been mentioned quite a few times.
Maybe you should read the thread.
I have read the thread quite carefully.
Maybe you should do the same because the points you seem to be missing are that a) not everyone is reporting performance issues -- many are just expressing concern about the numbers Activity Monitor reports & make no mention at all of any specific performance problems, b) few reports contain enough details to tell if there really is a memory use issue, & c) these issues have several different causes, not all of which are directly related to memory use.
Basically, you are assuming that a lot of users have exactly the same problem you do & it has exactly the same cause. It remains to be seen if that is a good assumption or not.
There are at least 5 posts about memory issues just on the first page. And at least 4 posts that directly come out and talk about Performance issues like Sluggishness. Not to mention a few posts about OS X consuming memory over the course of the day without the computer even being used.
So again, try reading the thread.
-
Jul 28, 2011 8:40 AMby mightymilk,R C-R wrote:
mightymilk wrote:
Compare your Windows/Linux machine at home your Mac, and you'll find they aren't using anywhere near the same amount of resources, even if they're running the exact same tasks.
No two different OS's ever run "the exact same tasks." If they did, they would be the exact same OS.
Earlier you said you were not trying to insult anyone's intelligence, but you seem to be doing a fairly good job of that now.
That's because you're being completely unhelpful, essentially posting FAQ sheets about how PFing and Activity Monitor work. You're ignoring the fact that Safari is using well over 1+ GB of RAM with one tab open, Mail in some cases is using 4+ GB of RAM, and the system itself overtime is eating up all available RAM while doing anything. Your also ignoring the fact that OS X has NEVER fucntioned like this previously. There are different people reporting the same problem... that right there should tell you something.
Imagine if you we're having problems with high CPU spikes under OS X, and I spend all day posting FAQs about how Activity Monitor and Processor cycles are handled under OS X. Does that solve your problem?
Are you really going to tell me that it's normal for OS X to consume all Free and Inactive RAM if it sits untouched for a day? Are you really going to claim that Safari with one tab open should be using 1+ GB plus of RAM. Are you really going to tell us it's normal for Mail to be using 4GB of RAM?
This is not typical behavior for OS X. It wasn't common under Snow Leopard, Leopard, or any other previous version. Anyone who's used OS X before knows this isn't typical behavior.
-
Jul 28, 2011 8:37 AMby ColoradoiPodUser,Okay, I hear all that.
But why would Activity Monitor report such different information, specifically free memory, then was reported under OS X 10.6.x?
It is the difference that had me so concerned.
I'm going to watch both Page Outs and Inactive over the next couple of days along with general performance.
Thanks for your, and everyone's input
-
Jul 28, 2011 8:58 AMby R C-R,Actually, you are the only person specifically mentioning performance issues on page 1. A few others talk about high memory use, but it isn't clear if performance is suffering because of that. At least one user on that page reported no abnormal memory use, & another that it disappeared when they uninstalled Flash.
And no matter how often users trying to help suggest checking & posting page out info, most are not doing that, despite the fact that it is the most useful info Activity Monitor provides about memory use.
If you are firmly convinced this is a problem inherent in the OS or Safari or whatever, & that only Apple can solve it, there is no point in continuing the discussion. We are just users, & if that is true then there is nothing we can do about it besides wait for a fix from Apple or suggest reverting to the last system that worked for you.
Of course, there is the fact to consider that some users are reposting no abnormal memory use, & that there are other factors that are known to cause performance issues, so just maybe there is something to do besides just waiting ….
