OS X Memory Allocation

Discussion in 'Mac Pro' started by dr01dy, May 15, 2007.

  1. dr01dy macrumors member

    May 3, 2007

    Can someone explain to me how OS X allocates its memory I am confused on a few things.

    I have 3 gigs of ram

    Wired 482MB
    Active 1.01Gig
    Inactive 1.48Gig
    Used: 2.97GB
    Free 32.74MB

    Does this mean I am running out of ram or does it mean I have 1.48gig free

    Also I notice that I have alot of page in's and not alot of pages out which means its not writing to the hard drive.

    Thanks !
  2. diehardmacfan macrumors regular

    Mar 12, 2007
    you need some more ram

    you have 32 megs free

    when the amount of free ram gets down to about 10 megs then it will start writing to the hard disk and you will see page outs
  3. dr01dy thread starter macrumors member

    May 3, 2007
    Thanks for the reply I guess I am just doing too much at once. I have eyetv converting a movie and ripping out commericals on another rip and Transmit running at 11000k a sec file transfer.

    I will see how it is when the rips are done.
  4. slughead macrumors 68040


    Apr 28, 2004
    No, you're OK.

    The 'inactive' RAM is being used to cache various pieces of commonly used data (based on your computer-using habits). Should you need more RAM for a task, the inactive RAM will be used to perform said task. In the meantime, the inactive RAM will speed up tasks like opening commonly viewed windows in the finder and stuff like that.

    This is the reason why OS X runs so much faster with more RAM: it caches lots of stuff automatically.
  5. dr01dy thread starter macrumors member

    May 3, 2007
    I thought it was odd.. looking at my Activity Moniter it says that kernel_task is using 1.59gigs of virtual memory.

    Do you think I need to upgrade to 6gigs instead of 3 ??
  6. slughead macrumors 68040


    Apr 28, 2004
    I wouldn't.
  7. JHacker macrumors 6502


    Aug 27, 2006
    East Coast
    This is a false statement. Don't listen to this guy because he's wrong. Inactive RAM & Free RAM added together equals your total unused RAM. You're fine and have 1.48 gigs free.
  8. lssmit02 macrumors 6502

    Mar 25, 2004
    Here's what Apple says about it:

  9. dukebound85 macrumors P6


    Jul 17, 2005
    5045 feet above sea level
    um wrong. please dont bother misleading people. inactive ram is free ram as well. to check if you need more ram, look at yout page in to page outs ratio in activity monitor. if they are somewhat comparable you need more ram

    edit: realized i should read entire thread before posting lol
  10. dr01dy thread starter macrumors member

    May 3, 2007
    Thanks for all the help I understand whats going on now. I have tons of free memory I am really only using about 20% of my total over all.

    Thanks again!
  11. Lundberg02 macrumors newbie

    Sep 4, 2012
    That's not what actually happens, no matter what Apple says. Disk accesses apparently eat up RAM into inactive and when Free RAM gets down into the Mb range, your Mac will slow to a crawl. This problem has become considerably more annoying since 10.8.4 and is almost insufferable in 10.8.5 with supplemental. I have 8 GB RAM. I used to have to purge (using iFreeMem) once a week. Now I have to do it several times a day. I tried to pin down the constantly increasing Inactive to an app, and thought I could blame Safari, but it proved futile. Last night out of the blue something started eating RAM at the rate of about 100Mb per minute. This has happened before under different numbers of apps open, windows in Dock, etc. I had to reboot three times in a half hour to stop it. Other craziness was going also.
  12. MacVidCards Suspended

    Nov 17, 2008
    Hollywood, CA
    Holy exhumations, Batman !!! A 6 year old post !!!

    Probably not waiting for an answer anymore.
  13. sunnyj macrumors 6502

    Oct 18, 2010
    Vancouver, British Columbia
    MacVidCards, you have anther pm. Please get back to me:)
  14. pastrychef macrumors 601


    Sep 15, 2006
    New York City, NY
    Yes, I agree. Mountain Lion does a pretty poor job of handling memory/cache. Fortunately, it seems like Mavericks has completely corrected this.
  15. OS6-OSX macrumors 6502a


    Jun 13, 2004
    It was here in this 6 year old thread, I thought I lost it in the dryer!:D

    Attached Files:

    • Sox.jpg
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      133.5 KB
  16. Saltymac, Oct 17, 2013
    Last edited: Oct 18, 2013

    Saltymac macrumors member

    Aug 19, 2013
    Rocky Mt State
    Consider users thought 3 GB of RAM was good in 2007 and the answers given. My 2008 new MacPro back then shipped with 2 GB of FB Ram which worked with Leopard fine until the 3 rd. party software and OS X's changed. Even Apple has finally upped base offerings to 8 GB in the 15' iMAC.
  17. bernuli macrumors 6502

    Oct 10, 2011
    I think you could benefit from more RAM, though the lack or RAM may not be slowing you down. As you said it is not paging. OS X should use up the inactive before paging and you have over a gig free.

    However, more RAM means that more can be cached. Any file that is opened or copied (big files too) ends up in RAM and will stay there as long as there is ram available, they just hang out in the inactive area.

    For what I do, I always get the max RAM. Huge payoff for me over time.


  18. MultiFinder17 macrumors 68000


    Jan 8, 2008
    Tampa, Florida
    I love it when threads get randomly dug out from their graves :D

    Attached Files:

  19. Gav Mack macrumors 68020

    Gav Mack

    Jun 15, 2008
    Sagittarius A*
    Truly one from the grave. I thought it would take a lot to max out the maximum 8 on my MBP 3 years ago how wrong I was. I'm finding it rather nice with 32gb on the 3,1 now though :D

    Most customers now on Mac's or PC's who need a refresh I max out their memory, unless the prices for their type are ridiculous like 4gb DDR2-800 desktop ram
  20. kevink2 macrumors 65816

    Nov 2, 2008
    I'm settling for 20 GB myself on my 08.

    Not that I had any real use for it. But I COULD :)

    Another 8 GB would get me to 26GB, but it would be a waste for my usage.

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