Page outs and restarting

Discussion in 'Mac Basics and Help' started by rye9, Feb 25, 2006.

  1. rye9 macrumors 65816

    rye9

    Joined:
    Sep 20, 2005
    Location:
    New York (not NYC)
    #1
    I understand that when page outs occur, it means the hard drive is being used instead of RAM, right? So when you restart, what happens with the HD and page outs, does it just delete what was used by the HD?
     
  2. calebjohnston macrumors 68000

    calebjohnston

    Joined:
    Jan 24, 2006
    #2
    I believe it really just refreshes your count. Why? Are you worried about your page-outs?
     
  3. rye9 thread starter macrumors 65816

    rye9

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    Sep 20, 2005
    Location:
    New York (not NYC)
    #3
    Not really, I was just concerned that page outs take up HD space and might over time accumulate bc i dont know how they are "deleted".
     
  4. calebjohnston macrumors 68000

    calebjohnston

    Joined:
    Jan 24, 2006
    #4
    High numbers of pageouts (multiple thousands) really just signify that you need more ram. If you only get a few hundred of the matter of a few days, then don't worry. I get 430 or so after 4 or 5 days. Just restart and it resets. Doesn't effect your computer.
     
  5. rye9 thread starter macrumors 65816

    rye9

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    Sep 20, 2005
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    New York (not NYC)
    #5
    Well I have 1397 and the last restart was when 10.4.5 came out. (the 15th, i think) Well actually, I shut my iBook down and turned it on two days later, but that doesnt mean anything.:D
     
  6. terriyaki macrumors 6502a

    Joined:
    Aug 4, 2005
    Location:
    Vancouver
    #6
    since this is kind of related i guess i'll ask here instead of making another thread..

    is there a command i can type in terminal that will free up my inactive ram?

    i faintly remember someone sharing a command like this here on the forums before.
     
  7. mad jew Moderator emeritus

    mad jew

    Joined:
    Apr 3, 2004
    Location:
    Adelaide, Australia
    #7
    The system assigns a portion of your hard drive to page ins and page outs. This is called Virtual RAM and can be read in Activity Monitor. Mine is 7.3GB which is about normal. It is this Virtual RAM that is the reason behind keeping at least 8GB of free space because you don't want the system having to cut back on Virtual RAM simply because you don't have the space. :)

    We don't want to clear Inactive RAM (I don't know how, but Google may help) because theoretically it can potentially be faster than Free RAM assuming you do the same tasks often. If you don't do the same tasks often, then it'll get reassigned to another task. :cool:

    In terms of memory, all we have to worry about is that free space on the hard drive and the rate at which page ins and page outs accumulate. If the system is acting sluggish then check that you're not getting massive amounts of Virtual RAM usage (restart to reset the counter) and check to see you have lots of free space. :)
     
  8. Glenn Wolsey macrumors 65816

    Glenn Wolsey

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    New Zealand
  9. calebjohnston macrumors 68000

    calebjohnston

    Joined:
    Jan 24, 2006
    #9
    I only have 512 ram, so I'm sure that's why I had some. You really need 1 gig for modern operating systems. It'll be a long time before thats default in laptops though I suppose.
     
  10. SmurfBoxMasta macrumors 65816

    SmurfBoxMasta

    Joined:
    Nov 24, 2005
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    I'm only really here at night.
    #10
    Well, after 4 days & massive amounts of work, I still have Ø pageouts :)
    but then again, I have 2GB ram & ~30GB free HD space too .......
     
  11. ElectricSheep macrumors 6502

    ElectricSheep

    Joined:
    Feb 18, 2004
    Location:
    Wilmington, DE
    #11
    The number you see in the Activity Monitor for 'VM Size' has nothing to do with how much space on your hard disk is actually being used for the purposes of the Virtual Memory Subsystem. One must remember that the Virtual Memory system of MacOS X is little like that of Classic.

    I can, for example, write a very small application that will increase the 'VM Size' figure by no less than 2 gigabytes, but the free space on my hard disk will remain completely unaffected. I could then run multiple copies of this program, boosting the 'VM Size' by gigabytes and gigabytes; still the amount of space on my disk used will remain unaffected.

    I can also write a tiny program that will generate lots and lots of pageouts. All I have to do is allocate a huge address space (about two gigs) and start writing random data to it. Once the program exits, i'll have a huge pageout count but won't necessarily be consuming a lot of memory.

    'VM Size' is a record of the total size of the Virtual Address Space. Disk space is not needed until allocations across the Virtual Address Space occur, and then they are handled on a page-by-page basis (a page being 2 kilobytes, IIRC). A process called the dynamic_pager is responsible for creating and managing the files that will contain these pages. In its default configuration, the dynamic_pager creates these pagefiles in 64 megabyte chunks, but if the demand is high enough it will increase that increment by factors of two until the systems paging requirements are satisfied. Thus, one might have four pagefiles on their system: two at 64 megabytes, one at 128 megabytes, and a fourth at 256 megabytes. It is possible to alter the configuration of the dynamic_pager to alter how these files are created and managed, but this requires some technical knowhow and modification of system files.

    The pagein and pageout counters are cumulative over time, and never go down. I wouldn't use them as an estimate as to how many memory pages are actually paged out to disk, nor if it means you need to invest in more memory. Indeed, as mentioned before, what is more important is the rate of pageouts. If you are paging out a lot under a normal workload, its a probably a good idea to invest in more real memory.
     
  12. Eithanius macrumors 65816

    Joined:
    Nov 19, 2005
    #12
    I'm seriously in need of RAM....

    restarted 7 hours ago, and I'm paging out like mad - 23K+ and rising... :eek: :eek:
     
  13. calebjohnston macrumors 68000

    calebjohnston

    Joined:
    Jan 24, 2006
  14. mad jew Moderator emeritus

    mad jew

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    Apr 3, 2004
    Location:
    Adelaide, Australia
    #14

    Good point but isn't it merely a technicality based on when space is allocated then. You're right though, I probably could have explained myself better. :)
     
  15. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #15
    4 Days, 17 hours, 36 minutes of uptime

    My page outs are kinda of starting to bother me even with 1.5 GB installed. I think it's related to 10.4.5.
     
  16. mad jew Moderator emeritus

    mad jew

    Joined:
    Apr 3, 2004
    Location:
    Adelaide, Australia
    #16
    That's quite high but your combined Free and Inactive Memory (which is the memory that's available to new processes) comes to over 1GB at the time of the screenshot.
     
  17. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #17
    Yeah, I know I do have a lot of free and inactive memory. It's just you hear so much about page outs and getting more RAM if you have tons. Then again I'm getting close to 5 days of uptime. I've just used Safari, iTunes, Mail, Skype, and Azureus. I think it's a toss up between Skype and Azureus causing so many page outs.
     

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