Is there a 32GB virtual memory limit in OSX?

Discussion in 'Mac Programming' started by omvs, Jul 21, 2013.

  1. macrumors 6502

    May 15, 2011
    Does OSX have a hardcoded limit of 32GB virtual memory per task? I have a cad program (glade) that I'm trying to load a very large design into, and it seems to be crashing at ~32GB.

    If this is a known limitation, is there a way to workaround this besides running another OS (linux, etc)?

    Not exactly a programming question (though I could probably rebuild the tool from the source code if I had to), but I suspect I'm more likely to get the right eyeballs here....

  2. macrumors 68000

    Mar 29, 2009
    32GB is not the limit. I have seen a memory leak consume all 8GB of RAM and all the free space on a 256GB SSD, in a 13" Air right out of the packaging (iCloud contacts sync bung). You may be hitting some other limit, like stack size. How much free disk space do you have? If you run 'ulimit -a' at the terminal you should see some information:

    $ uname -a
    Darwin Rocket.local 12.4.0 Darwin Kernel Version 12.4.0: Wed May  1 17:57:12 PDT 2013; root:xnu-2050.24.15~1/RELEASE_X86_64 x86_64
    $ ulimit -a
    core file size          (blocks, -c) 0
    data seg size           (kbytes, -d) unlimited
    file size               (blocks, -f) unlimited
    max locked memory       (kbytes, -l) unlimited
    max memory size         (kbytes, -m) unlimited
    open files                      (-n) 256
    pipe size            (512 bytes, -p) 1
    stack size              (kbytes, -s) 8192
    cpu time               (seconds, -t) unlimited
    max user processes              (-u) 709
    virtual memory          (kbytes, -v) unlimited
  3. macrumors 68040

    Feb 2, 2008
    The first suspect is Glade I would think, perhaps you could try on a Glade specific forum and see what that turns up. Also, are you sure you have ~32GB of available memory?
  4. macrumors 65816


    Oct 19, 2012
  5. thread starter macrumors 6502

    May 15, 2011
    Interesting info - thanks to all.

    I do have a boatload of disk space, and the crash happened right around 32G of virtual memory (watching it in Activity Monitor). That made me wonder about a 32G limit in the os, plus I thought I had read something about this months ago, but couldn't not find anything using google. Physical memory I only have 24G right now (my 4th 8GB SODIMM is bad and being replaced).

    Last night I did manage to read the updated design in and it succeeded using 31.8GB. Hopefully thats good enough -- this is just for a backup plan if I need to view the design while our work computers are being moved from one site to another.

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