Question about RAM

Discussion in 'MacBook Pro' started by jamesryanbell, Aug 16, 2010.

  1. jamesryanbell macrumors 68020


    Mar 17, 2009
    I have a C2D Duo 2.53 (late 2008) with 4GB of RAM. When I run iStat, it lists four categories of memory, and I don't understand what they mean.


    My question is this: What is the difference between "inactive" and "free", and what's the difference between "Wired" and "Active"?

    I keep running out of memory, and it's saying I always have between half a gig and one gig of "inactive" memory, while almost nothing is "free" (5-25 MB). ?? Then pinwheel madness ensues.

    Keep in mind I'm not running *anything* memory intensive. My open programs at the time were: iTunes, Pages, Calendar, Safari, Mail, Firefox, and Preview.

    Just wanted to get insight from the pros. :) haha.
  2. celticpride678

    Feb 15, 2009
    Boston, MA

    Free memory

    This is RAM that's not being used.

    Wired memory

    Information in this memory can't be moved to the hard disk, so it must stay in RAM. The amount of Wired memory depends on the applications you are using.

    Active memory

    This information is currently in memory, and has been recently used.

    Inactive memory

    This information in memory is not actively being used, but was recently used.

    For example, if you've been using Mail and then quit it, the RAM that Mail was using is marked as Inactive memory. This Inactive memory is available for use by another application, just like Free memory. However, if you open Mail before its Inactive memory is used by a different application, Mail will open quicker because its Inactive memory is converted to Active memory, instead of loading Mail from the slower hard disk.
  3. jamesryanbell thread starter macrumors 68020


    Mar 17, 2009

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