How to free up inactive memory?

Discussion in 'MacBook Pro' started by BB.King, Aug 6, 2012.

  1. BB.King macrumors regular

    Jun 29, 2012
    London UK

    I'm experiencing sluggish UI change with my retina macbook pro, upon checking Active Monitor, it seems I'm running out of memory.

    Whats puzzling is the OS holding on to 2GB of ram as inactive memory even when the hard drive is been used as virtual memory. My understing is the OS should free up inactive memory as free memory runs out. So why would the OS not release the extra memory? It this a Mountain Lion bug or some kind of design feature I'm not aware of?

    Many thanks

    P.S. How come the VM size is 384GB when the hard drive is only 256GB?

    Attached Files:

  2. stevelam macrumors 65816

    Nov 4, 2010
    VM size has absolutely nothing to do with hard drive space. if you don't know what it is, don't worry about it.

    and there really is no point in freeing up inactive memory. all it is is recently used ram for programs. if you use that program again it will load from ram. its still free for use for other applications if need be.
  3. Nielsenius macrumors 6502a

    Apr 16, 2011
    Run the following command in Terminal:


    That should free up all inactive memory.
  4. heisenberg123 macrumors 603


    Oct 31, 2010
    Hamilton, Ontario
    inactive ram is free ram if you really anal about moving in back to the Free Ram total an app like Free Memory would do that but again its pointless
  5. rlantagne21 macrumors member

    Jul 29, 2012
    Close some apps already, looks like you have everything running at once... The inactive memory is memory that isn't currently being used, but it from apps that were recently closed. This is why when you first turn on your computer and open an app, it may take a second or so to open. If you quit the application, wait a few seconds, then open it again, it opens almost immediately. If you were to start opening more applications right now, OSX is smart enough to eliminate some of the inactive memory for the new application before it will start paging files on your hard drive. However, it looks like you barely have any free memory left, which may cause some paging to happen.
    ..But like one of the previous posts said, if you wish to free all inactive memory, the purge command works fine.
  6. gentlefury macrumors 68030

    Jul 21, 2011
    Los Angeles, CA
    It actually isn't pointless. ML handles inactive ram better than Lion did. But when Lion first came out I had many occasions where I would have like 200MB free and several GB in inactive and the entire system would crawl until I ran purge.

    ML seems to not have this problem, thankfully. But it was an issue.
  7. smithrh macrumors 68020


    Feb 28, 2009

    Something *was* broken in both SL and Lion with memory management.

    However, it's fixed now in ML. Typically in SL and Lion I'd have to take some action (usually rebooting) to stop the swapping/beachballing every 4-5-6 days. Even with high amounts of free/inactive memory and no apps running I'd get pageouts.

    At this point with ML I've been running for a solid 2 weeks w/o a single pageout - and obviously I've not needed to reboot to reclaim/restart memory.
  8. PS65 macrumors 6502

    Jan 25, 2008
    United Kingdom
    What a stupid bit of advice! He is not worrying, he is taking an interest and asking for help.

    People moan that others come to this forum asking questions - but when you give a rubbish response like that, then no one will learn and this forum becomes pointless, like your comment.
  9. VacTacks11 macrumors member

    Aug 24, 2009
    I use a program called FreeMemory. It's free (extras can be unlocked for $0.99), and can be bought it in the App Store. Sits in the Taskbar, and when I need extra memory (for example, when I have VMWare open), or when I feel it like it, I just click on the current RAM Free, then choose 'Free Memory'
  10. yusukeaoki macrumors 68030


    Mar 22, 2011
    Tokyo, Japan
    I agree with everyone.
    SL and Lion had something missing on free RAMs.
    It wasn't somehow right.

    But in ML, it handles them better.
    I just restart my Mac once in a while.

Share This Page