iStat Pro -- is this stat correct??

Discussion in 'MacBook Pro' started by NickM, Mar 16, 2009.

  1. NickM macrumors 6502

    Joined:
    Feb 24, 2009
    Location:
    USA
    #1
    According to iStat Pro, I only have 2.31gb of RAM that is not in use...

    My MacBook Pro has 4gb, and I have no programs running.
    Does that seem normal??
     
  2. wetrix macrumors 6502

    wetrix

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    Dec 1, 2006
    Location:
    Auckland, New Zealand
    #2
    Yes. You may have opened programs and closed them but they remain in your memory. Also, the OS uses what it can get.
     
  3. NickM thread starter macrumors 6502

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    USA
    #3
    Obviously I'm new to the world of Macs...
    So even though programs are closed, the memory is still being used on them?
    That seems odd to me.
     
  4. wetrix macrumors 6502

    wetrix

    Joined:
    Dec 1, 2006
    Location:
    Auckland, New Zealand
    #4
    Yes, but it's given a low priority. If an active program needs more ram, it'll take it off the closed programs. You shouldn't worry about your ram not being free - it just means you're actually using what you've paid for.
     
  5. NickM thread starter macrumors 6502

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    #5
    Also...
    Approximately how much RAM does OS X usually take up by itself?

    I don't like the idea of not being able to see exactly how much RAM is not being used... even if I've already opened and closed lots of programs.
     
  6. NickM thread starter macrumors 6502

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    #6
    I'm not worried about anything.
    Being able to see a number that informs me of how much RAM is actually free just sounds like a necessity to me.
     
  7. xoggyux macrumors 6502

    Joined:
    Dec 4, 2008
    #7
    Wired memory is what you are actually using: usually for me is about 1.5GB but I have lots of programs opened like safari audium mail ical itunes word utorrent iphoto.
    Inactive memory is memory that at some point in time was used but OS X did not clean it just in case you want to use that same program in the future and it will load faster, also if at some point in time you need that memory OS X will instantly clean it up (so its basically free memory sticking around "just in case").
    Free memory = system memory - used memory - inactive memory.
     
  8. Earendil macrumors 68000

    Earendil

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    Oct 27, 2003
    Location:
    Washington
    #8
    But memory is a very fluid thing, and being "in use" is hardly a black and white situation. If you want to know whether you need more RAM or not, than just watch for it being full. Also, the Page in/outs are important, as they demonstrate when programs want Main memory but are instead relegated to using the HD. Some Page in/outs are normal, but there is an excessive amount that I can't put my finger on off the top of my head.

    If you are worried about memory usage because you are testing software, than the activity monitor isn't what you want anyway.
     
  9. NickM thread starter macrumors 6502

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    Feb 24, 2009
    Location:
    USA
    #9
    Cool... thanks for the informative replies.
    I'm basically brand new to Mac computers...just got my first MacBook Pro
    and I'm trying to get a feel for how it operates, how it idles, etc.

    Another reason I was wondering is because even if I add up all the RAM-related
    numbers in iStat Pro, they still don't add up to 4gb.
     
  10. doubletap macrumors regular

    Joined:
    Jan 2, 2009
    #10
    Always remember:

    Unused memory is wasted memory.

    DT
     
  11. NickM thread starter macrumors 6502

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    Feb 24, 2009
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    USA
    #11
    Slightly clever comment, but that's not what I was looking for.
    My question has been answered.
    Thanks!
     
  12. MacUser2525 macrumors 68000

    MacUser2525

    Joined:
    Mar 17, 2007
    Location:
    Canada
    #12
    Probably just what they are choosing to show you not adding up look at the PhysMem line in the output of top run in a Terminal window it should show all when you add the used and free parts.

    Code:
    PhysMem: 1722M wired, 1684M active, 4690M inactive, 8101M used,   91M free.
     

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