4 Replies Latest reply: Oct 10, 2012 4:09 AM by rthorderson
rthorderson Level 1 Level 1

I just installed 10.8.2 onto a fresh drive on my Mac Pro 3,2 18GB Ram, 2x2.8GHz Quad. Everything is great EXCEPT I can't get the Kernel to run in 64-bit mode. My old 10.6.8 is still available and so I booted to that, and was able to run in 64-bit just fine. Also odd is that there is no information in the System Profiler under System Software Overview...where it should say 64-bit Kernel and Extensions [yes/no], there is no line at all (there is in 10.6.8). I am using that little Startup Mode Selector App to see if the kernel is in 32-bit.


Kernel Version is Darwin 12.2.0


I am stumped...



Mac Pro, OS X Mountain Lion (10.8.2)
  • Retired Engineer Level 4 Level 4

    Open Activity Monitor and select the CPU tab.


    Look for PID 0  kernel_task.


    At the right side it will say (64 bit).


    Mountain Lion is 64 bit by default.

    I don't think a 32 bit kernel even exists.

  • rthorderson Level 1 Level 1



    No PID 0 is displayed (or anything named kernel_task). Everything in the Process List is running with kind = 64bit, but from my reading, that doesn't mean the 64bit kernel is running. Also, my MacPro 3,1 is one of the oldest machines that WILL run 10.8.2, but it also has the distinction of not defaulting to 64bit (at least that is my understanding), where newer machines will.


    I may be OK, but it would be nice to be able to confirm definitively...


    In the terminal, a uname -a produces this...


    Randys-Mac-Pro:~ randythorderson$ uname -a

    Darwin Randys-Mac-Pro.local 12.2.0 Darwin Kernel Version 12.2.0: Sat Aug 25 00:48:52 PDT 2012; root:xnu-2050.18.24~1/RELEASE_X86_64 x86_64


    Is the bold my confirmation?



  • Retired Engineer Level 4 Level 4

    Change the display mode at the top right of the screen to

    All Processes


    PID 0 must be there.  The machine can't function without it.

  • rthorderson Level 1 Level 1

    Ahhhh, PERFECT...changed Activity Monitor to ALL PROCESSES and the kernal_task is indeed running as kind = 64bit.