Does page-in reset after reboot

Discussion in 'MacBook Pro' started by gngan, Apr 27, 2013.

  1. gngan, Apr 27, 2013
    Last edited: Apr 27, 2013

    gngan macrumors 68000

    gngan

    Joined:
    Jan 1, 2009
    Location:
    MacWorld
    #1
    As the title say.

    Does it?


    Edit: I know what page out means but can someone explain to me what page in is? I happen to have 60gb of page in and 0 page out.

    The other day while i was using Bit torrent, nothing else was opened but I had like 1gb of page out. Is that normal?
     
  2. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #2
    Yes, but there's never any need to worry about page ins. You will always have them. The only thing to watch for is page outs, which may indicate you don't have enough RAM.
     
  3. johnnnw macrumors 65816

    johnnnw

    Joined:
    Feb 7, 2013
    #3
    https://discussions.apple.com/thread/3033663?start=0&tstart=0

    Page-ins are a normal function, nothing to worry about what so ever.

    ----------

    It was explained to me if page outs are 1GB or more appox. then you should consider more RAM.
     
  4. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #4
    To determine if you can benefit from more RAM, launch Activity Monitor and click the System Memory tab at the bottom to check your page outs. Page outs are cumulative since your last restart, so the best way to check is to restart your computer and track page outs under your normal workload (the apps, browser pages and documents you normally would have open). If your page outs are significant (say 1GB or more) under normal use, you may benefit from more RAM. If your page outs are zero or very low during normal use, you probably won't see any performance improvement from adding RAM.

    Using Activity Monitor to read System Memory and determine how much RAM is being used
    That's actually not accurate. If an application calls a page and it's already in RAM, no paging occurs, since the page is already in RAM. If an app calls for a page that is located on the drive, a page-in occurs, to move the page into RAM. When there is insufficient available RAM to accommodate the incoming page, a page from RAM must first be written out to the drive to make room for the incoming page. That is a page out.
     
  5. johnnnw macrumors 65816

    johnnnw

    Joined:
    Feb 7, 2013
    #5
    My bad. I copy pasted it from the Apple discussion, it was posted by a mod or some influential poster so I assumed it was accurate.
     
  6. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #6
    So you don't have to take my word for it (after all, I'm just another poster), here's Apple's statement:

    From: Using Activity Monitor to read System Memory and determine how much RAM is being used

    For more details, this may help: Memory Usage Performance Guidelines: About the Virtual Memory System
     
  7. johnnnw macrumors 65816

    johnnnw

    Joined:
    Feb 7, 2013
    #7
    Dude I wasn't questioning you, it was a sincere my bad in that I posted bad information. I totally believe and agree with you. Maybe my tone came across different I'm not sure but I agreed I was wrong.
     
  8. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #8
    I know you weren't questioning me. Your tone was fine. That's why I usually post links to my sources of information: because there's so much misinformation on the web. I just wanted to give you the benefit of a more authoritative source, rather than taking anyone's word for it. We're cool.
     
  9. gngan, Apr 28, 2013
    Last edited: Apr 28, 2013

    gngan thread starter macrumors 68000

    gngan

    Joined:
    Jan 1, 2009
    Location:
    MacWorld
    #9
    Hey there,

    First of all, thank you for taking your time replying.

    I know all the stuff you said about Activity Monitor. I've never had page out since i upgraded to 8gb ram until that day while i was using Bit Torrent client (no other apps were opened). I am wondering if that's normal.

    I just restarted my Mac to see if the page-in is reset. Without opening any apps except Activity Monitor, it says there's 2xxmb. How is that possible?
     
  10. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #10
    There are always processes running in the background, even if you haven't launched any apps. Launch Activity Monitor and change "My Processes" at the top to "All Processes" and you'll see what I'm talking about. As soon as you boot your Mac, it needs to bring data into RAM in order to operate, even if the only thing running is OS X. That results in page ins. If you had nothing in RAM, your computer wouldn't be running. RAM contents are emptied during a restart, so page ins begin when you start up again.
     

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