"low free memory" what to do?

Discussion in 'Mac Apps and Mac App Store' started by milligan, Aug 30, 2011.

  1. milligan macrumors member

    Joined:
    Jul 20, 2009
    #1
    I installed the app "check up"
    http://www.adnx.com/software/checkup4mac.html

    It solved a few problems for me and I'm happy with it.

    However it is showing an alert when I have only a few apps open
    "low free memory"

    I have
    free memory 155mb
    inactive memory 943mb
    active memory 2.13gb
    wired memory 560 mb
    used memory 3.60gb

    Vram size 256mb

    Is this a problem for me? Is it making things slower. What should I do?

    Thanks
     
  2. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #2
    With OSX, free memory is wasted memory.

    What's your page-outs look like. That is a better measurement of whether you're short on ram. High page-outs indicate a high volume of disk IO to swap ram pages to the disk
     
  3. gnasher729 macrumors P6

    gnasher729

    Joined:
    Nov 25, 2005
    #3
    Wired memory = memory that the Mac absolutely needs.
    Active memory = memory that is actively used right now.
    Inactive memory = memory that holds things that might be useful in the future or not; if your Mac needs more Active memory it will use Free memory first, then Inactive memory, both at no cost.
    Free memory = memory that the Mac has never, ever felt any need to use.

    You have over one GB "Free" and "Unused" memory; that is plenty.
     
  4. milligan thread starter macrumors member

    Joined:
    Jul 20, 2009
    #4
    With OSX, free memory is wasted memory.

    What's your page-outs look like. That is a better measurement of whether you're short on ram. High page-outs indicate a high volume of disk IO to swap ram pages to the disk


    Thanks for the help guys. So I wonder why its showing up as an alert.

    I have no idea about pages out.... where would I see that?

    Thanks
     
  5. steveoc macrumors regular

    Joined:
    Nov 6, 2007
    Location:
    Adirondacks NY
    #5
    Pages out can be seen in the Activity Monitor with system memory toggled:

    [​IMG]

    In my opinion, RAM is cheap and life is better with plenty of it.
     
  6. Peace macrumors Core

    Peace

    Joined:
    Apr 1, 2005
    Location:
    Space--The ONLY Frontier
    #6
    I'm not advertising but there's a great app out there called Cocktail. He's been around for a long time and he just updated the app.

    What's great about it is it allows you to purge the inactive memory on the fly.

    Try it out.

    http://www.maintain.se/cocktail/index.php
     
  7. interrobang macrumors 6502

    Joined:
    May 25, 2011
    #7
    Well, I mean, Check Up has got do do something to justify €23, right? And Cocktail has to do something to justify that $20.

    I mean, there's not much point in selling software that says "Your Mac is running just fine, don't buy this software, because you don't need it." So if there isn't an actual problem you've got to say something, right?
     
  8. saberahul macrumors 68040

    Joined:
    Nov 6, 2008
    Location:
    USA
    #8
    What if my page outs is at a value of 1.5GB and my page ins is at a value of 9.8GB. Is that bad?
     
  9. accessoriesguy macrumors 6502a

    Joined:
    Jul 8, 2011
    #9
    that means you could use more RAM
    i'm guessing you've been getting symptoms of slowness, locking up, freezing like states, especially when having multiple applications open?

    if that's the case, upgrade your RAM today :D
     
  10. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #10
    That means you have some pages that have been swapped to disk (1.5gb worth) and OSX has been reading/re-reading those pages as needed. So while not bad, you can see how that could possibly impact performance since OSX needs to perform disk i/o instead of accessing the pages straight from ram.

    For instance I have 768k of page outs and 4.61gb of page ins. So its been reading/reading that small amount quite a bit but its only a small subset of pages.
     
  11. saberahul macrumors 68040

    Joined:
    Nov 6, 2008
    Location:
    USA
    #11
    Hmm okay. Thanks for the info. I may consider upgrading to 8GB down the line as I do a lot of memory intensive work.
     
  12. AmbiguousNinja macrumors regular

    AmbiguousNinja

    Joined:
    Jun 15, 2011
    #12
    Not an answer to your dilemma but for future reference, there is a "quote" button in the bottom right corner, next to the up and down vote buttons :)
     
  13. milligan thread starter macrumors member

    Joined:
    Jul 20, 2009
    #13
    Ah thanks. I have Pages out 630.3MB
    So is that high?
    I should get more RAM?

    Thanks!
     

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  14. hayesk macrumors 65816

    Joined:
    May 20, 2003
    #14
    Yes, it'll help.

    Off-topic rant - Am I the only one who thinks all of these system maintenance utilities like onyx, cocktail, etc. are a waste of time? From what I can tell, people who insist on using these end up having more trouble with their systems than those who don't.
     
  15. jcodirewolf macrumors newbie

    Joined:
    Jan 13, 2010
    #15
    Nope. Understanding CPU and Memory usage on Unix is not simple.

    The above poster who said-
    Wired memory = memory that the Mac absolutely needs.

    Thats not true. That is memory, typically kernel memory, that can NOT be swapped out. I guess you could say "absolutely needs" but it's just an odd way to put it.

    The total swapped in/out is not important, its the number after it the amount in/out per SECOND. That is using your disk bandwidth as memory, and disk is way slower than real memory. But a low level is normal, I think Mac OSX "preswaps" has a list of pages which haven't changed or used in a while, if you have some free cycles page it out, because it's a candidate for swapping.

    Low free memory is okay, because memory isn't freed until it's needed for something else, which is determined by some "low water mark". So the other thing you need to look for is memory freeing then being eaten back up quick and freed again.

    if you want to play with it check out sysctl-
    kern.vm_page_free_target: 2000
    kern.vm_page_free_min: 1500
    kern.vm_page_free_reserved: 100

    (pages are 4KB on my machine) so it wants 8MB free, you have 155MB free.

    Supposedly, Seymour Cray said "Memory is like sex, you can fake it but the real thing is more fun."

    johno

     

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