Apps eat my mac memory!!!!

Discussion in 'Mac Apps and Mac App Store' started by Black.Infinity, Jun 25, 2011.

  1. Black.Infinity macrumors 6502


    Apr 17, 2010
    Apple tree-Toronto
    I'm trying to understand some virtual memory strangeness I'm seeing.

    After a reboot, I have lots of free memory available. After a while, the amount of inactive memory increases until there's hardly any free memory left, at which point my system starts getting lots of pageouts.

    What is confusing to me is that this condition persists even after I kill all my applications. Even with no applications running, Activity monitor reports a large figure for inactive memory.

    It seems to me that when a an application process is killed, its physical pages should be returned to the free pool, and not left around
    as inactive.

    Or perhaps that's not what's happening, perhaps some hidden process is eating all my virtual memory.

    Does anyone have an explanation for why this happens?

  2. iBookG4user macrumors 604


    Jun 27, 2006
    Seattle, WA
    I believe that the Mac continues to store the most used portions in memory even after the application is quit. That's why an application starts faster the second time it is opened than the first. Although I could be wrong. A good way to clear up the memory is ifreemem or repairing permissions also should be able to achieve the same goal.
  3. richard.mac macrumors 603


    Feb 2, 2007
    51.50024, -0.12662
    this is a common worry here and you'll find many threads discussing this by searching.

    in a nut shell, inactive memory is filled up over time by apps/processes when they close, so they launch faster the next time.

    its normal for a little paging out to be done when your RAM is filled up by inactive memory as its still storing inactive memory for those apps. when you start getting A LOT of page outs, like 20% of your total RAM for example, and most of your RAM is being used by active memory, then you should be looking at getting more RAM.
  4. Black.Infinity thread starter macrumors 6502


    Apr 17, 2010
    Apple tree-Toronto
    thank you guys i guess i should just go buy more ram:)
  5. interrobang macrumors 6502

    May 25, 2011
    Wow, you're really intent on having unused memory, aren't you?

    Okay then, I suggest you buy a few sticks of ram and duct-tape them the outside of your Mac's case. Do not install them in your Mac. That way, you'll be absolutely sure that that memory is "free," and not filled with pesky programs or data. ;)
  6. chrono1081 macrumors 604


    Jan 26, 2008
    Isla Nublar
    OSX scales ram and uses what is available. Free ram is wasted ram.

    When I turn on my desktop and have nothing running except the OS, it takes about 4 gigs of ram. If I open Maya, Photoshop, and Unity it jumps to between 6 - 12 gigs. I have 24 gigs of ram total in my system.

    Now, if I open the same programs on my laptop, just turning on the machine I will use about 750mb to 1 gig for the OS, if I open Maya, Photoshop, and Unity it will use about 2.5 - 3 gigs of ram. (Out of 4).

    Unless you are truely in need of more ram, you should be just fine.
  7. mattraehl macrumors 6502

    Feb 26, 2005
    Nice. :D
  8. iSee macrumors 68040


    Oct 25, 2004
    No. To simplify: available RAM == inactive RAM + free RAM.

    Page outs aren't bad by themselves, even a large number. You've got to watch page outs as you do things:

    If page outs increase a bunch as you perform tasks that you wish were faster, then you will probably benefit from more RAM. Otherwise you probably won't.

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