Page outs with 12 gigs of ram?

Discussion in 'Mac Pro' started by bsmith1, Mar 21, 2008.

  1. bsmith1 macrumors newbie

    Joined:
    Jan 5, 2008
    #1
    I have a 3.0-8 core mac pro with 12 gigs of ram. I still get page outs...I thought that would not happen with that level of ram...

    Been up 1 day, 7 hours; 668,000 page ins, 4,351 page outs...also showing 7mb (64mb) swap file.

    Are these normal numbers? Do I need to tweak something?

    Thanks.
     
  2. killmoms macrumors 68040

    killmoms

    Joined:
    Jun 23, 2003
    Location:
    Washington, DC
    #2
    Yes they are normal, yes OS X will occasionally page small amounts of things even if you have lots of RAM, no, there is nothing to tweak.
     
  3. bsmith1 thread starter macrumors newbie

    Joined:
    Jan 5, 2008
  4. Brutus Rex macrumors newbie

    Joined:
    Jan 13, 2008
    #4
    i have 16 gigs of RAM

    16 gigs from OWC.
    uptime: 2 days, 8:14, 2 users, load averages: 0.20 0.17 0.10

    page ins: 4,125,685
    page outs: 45,370

    i need reassurance this is "normal"
     
  5. CanadaRAM macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #5
    As long as your Page Outs are under 5% of your Page Ins, you're golden.

    10% is acceptable, over 10% and start looking at upgrading.

    Don't worry about the absolute numbers, it's all about the ratio.

    OP - you gots under 1% Page Outs -- be happy!;)
     
  6. VoodooDaddy macrumors 65816

    Joined:
    May 14, 2003
    #6
    I used to obsess over page ins/out...but that was when I has 512mb in my mini, and even when I upped that to 1gb. Used to run about 2:1 in to out with 512. Obvioulsy that dropped when I installed 1gb, then dropped further when I put in 2gb.

    However, back then I used to hear ppl say when they put in 4gb of ram into their iMacs there NEVER had page outs. Got an iMac about a month ago, put in 4gb day 1.

    Currently, Im seeing page in 2.59gb, page out 252mb. This is with 17 days uptime. By my rough calculation Im at 10%. I dont really even look at this anymore since ram shortages seems to be a non-factor with 4gb.

    I would assume you guys are running Tiger since the page in/out is different on it than Leopard.
     
  7. Brutus Rex macrumors newbie

    Joined:
    Jan 13, 2008
    #7
    just curious how page in/outs are different between tiger/leopard.
    I am on leopard, early 2008 mac pro 3.0
     
  8. dukebound85 macrumors P6

    dukebound85

    Joined:
    Jul 17, 2005
    Location:
    5045 feet above sea level
    #8
    i dont think so....if you have free ram, why would osx write to the hd?

    simple answer...it wont

    you get page outs when the ram is no longer availiable and the hard drive must then be used to store the info.
     
  9. ekwipt macrumors 6502

    Joined:
    Jan 14, 2008
    #9
    if you don't have all 8 dimms filled you will only have 6.5-7gbs transfer rate when all 8 is filled you get 7.5 gb/s.

    So i'm guessing if at any one time your memory ( no matter how much you have) can't handle the amount of data being sent to it (in GB/s) then you will have pageouts
     
  10. Infrared macrumors 68000

    Infrared

    Joined:
    Mar 28, 2007
    #10
    What are the units of measurement above?
     
  11. Nermal Moderator

    Nermal

    Staff Member

    Joined:
    Dec 7, 2002
    Location:
    New Zealand
    #11
    I don't believe that the units matter, from what I can tell it's the ratio that's important.

    My MBP's been very slow recently and now I notice that my page outs are at 65% of my page ins (2.31 GB and 3.54 GB respectively). My RAM is maxed out (3 GB) so I'm wondering whether there are any other ways to improve performance.

    I'm doing a lot of work in VMware, dealing with large files (10-15 GB) so I suspect that that is a large part of the problem :) but I'm open for any suggestions.
     
  12. CanadaRAM macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #12
    Nope.

    Doesn't have anything to do with the bandwidth.

    Think about it a sec. The Mac sez "OMG i am getting only 6.5 Gb/s and I should be getting 7.5 !!! I better start using the hard drive that gets 0.8 Gb/s instead!!" ? -- don't think that's happening.
     
  13. macz1 macrumors 6502

    macz1

    Joined:
    Oct 28, 2007
    #13
    the unit should be in "pages", the memory unit the OS uses for the management of the logic memory ("virtual" and "real"). A typical page size is 4KB (I think also in OS X)
     
  14. gnasher729 macrumors P6

    gnasher729

    Joined:
    Nov 25, 2005
    #14
    It may not be a problem at all. The most common reason for page-outs is virtual memory being forced to write data to your hard drive because there is not enough real memory available, but that is not the only cause. An application can use file mapping, which means it "pretends" that a file is part of its memory. Instead of calling "read" and "write" functions in the OS, the application uses that file as if it was completely in memory, and relies on virtual memory to do all the actual reading. So all operations on that file will be shown under "page-ins" and "page-outs" in "System Memory" instead of "Data read" and "Data written" in "Disc Activity".

    You may have an application that does this kind of thing.
     
  15. RedTomato macrumors 68040

    RedTomato

    Joined:
    Mar 4, 2005
    Location:
    .. London ..
    #15
    I have 4gb in my MB, and I almost never ever get pageouts.

    7 days uptime, have done some intensive video work, had about 40 tabs open in Firefox, played a few flash games, done some hard work in Word, Photoshop and Dreamweaver, all open at the same time.

    Free: 1.5GB
    Wired 700MB
    Active 1.5GB
    Used 2.5GB

    VM size: 55GB (!)
    Page ins: 900MB
    Page outs: 0 Bytes
    Swap used: 0 Bytes.
     
  16. richard.mac macrumors 603

    richard.mac

    Joined:
    Feb 2, 2007
    Location:
    51.50024, -0.12662
    #16
    although you shouldnt really take notice of it the VM size in Leopard's Activity Monitor is a bug. to correct it add a non default column. mine is 7GB and my page ins/page outs is 142MB/0B with 1.5GB RAM after just rebooting from Windows.

    and for the users that are confused; Tiger's Activity Monitor uses page units for page ins/page outs while Leopard uses bytes.
     
  17. Infrared macrumors 68000

    Infrared

    Joined:
    Mar 28, 2007
    #17
    That may have once been the case, but now:

    pageouts.png

    So I have MB for page ins and B for page outs. If I had
    more page outs maybe they'd be measured in KB or MB.
     
  18. Infrared macrumors 68000

    Infrared

    Joined:
    Mar 28, 2007
    #18
    :)

    I wrote a little program to see what sort of VM
    figures would show up in the activity monitor:

    Code:
    #include <stdio.h>
    
    main()
    {
    	getchar();
    }
    For those who don't know C, it just waits for one
    character of input and terminates when it gets it.
    I compiled it as both a 32-bit and 64-bit executable,
    and here are the VM figures from the activity monitor:

    32-bit: 585.56 MB
    64-bit: 2.57 GB

    Obviously the program isn't using anywhere near to
    that amount of real RAM. I do wonder how those
    precise numbers come about, though.
     
  19. richard.mac macrumors 603

    richard.mac

    Joined:
    Feb 2, 2007
    Location:
    51.50024, -0.12662
    #19
    Virtual memory is just the amount of memory a process allocates. it doesnt necessarily have to use all of it. in most cases it wont. BTW what do i do with that code? i want to try it out. ive got Xcode installed.
     
  20. topgunn macrumors 65816

    topgunn

    Joined:
    Nov 5, 2004
    Location:
    Texas
    #20
    Do you ever put your computer to sleep?

    Check your page outs then put your computer to sleep. You should see the count go up slightly.
     
  21. RedTomato macrumors 68040

    RedTomato

    Joined:
    Mar 4, 2005
    Location:
    .. London ..
    #21
    My MB sleeps all the time. And sometimes the battery runs out and it falls asleep. Still 0 pageouts.

    I tried the trick of adding a non-default column, and my VM went from 55GB to 14GB.

    Still a little bit (!).
     
  22. topgunn macrumors 65816

    topgunn

    Joined:
    Nov 5, 2004
    Location:
    Texas
    #22
    Hmm, perhaps it is something that has changed in Leopard. I specifically remember doing this when I bumped my old iMac (Tiger or possibly Panther) to a then whopping 2GB of RAM and wondering why I still had pageouts. After putting the computer to sleep, I noticed I had more. But, I just tried it on my MBP with Leopard and it didn't change at all.
     
  23. Infrared macrumors 68000

    Infrared

    Joined:
    Mar 28, 2007
    #23
    Xcode is overkill for something like this. If you were
    to use Xcode then you'd start a new project like so:

    Picture 8.png

    Then you'd want to replace all the code in 'main.c' with my
    code above and you're ready to build and go.

    Alternatively, at the command line, bung that code in a file
    'main.c' and then compile it:

    Code:
    gcc -o aardvark main.c
    Then you can run it:

    Code:
    ./aardvark
    Oh, and why did I name it 'aardvark'? It's so I can sort
    it to the top of the process list in Activity Monitor :)
     
  24. itsallinurhead macrumors 6502

    itsallinurhead

    Joined:
    Apr 23, 2007
    Location:
    Southern California
    #24
    I have 0 page outs with 6gb. 134,998 pages ins...
     
  25. Thiol macrumors 6502a

    Thiol

    Joined:
    Jan 26, 2008
    #25
    I have 452,300 page ins and 0 page outs with 10 GB of RAM on a Mac Pro. It goes to sleep sometimes, so the sleep theory doesn't apply to my machine the way I use it at least.
     

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