1 Reply Latest reply: Apr 14, 2013 3:48 PM by BobHarris
Istalir Level 1 (0 points)

I'm trying to see if I'm starting in 64 bit mode on Snow leopard, However, the "64-bit Kernel and Extensions: Yes (or No)" does not show up where it's supposed to, wondering why.

MacBook, OS X Mountain Lion (10.8)
  • BobHarris Level 6 (17,634 points)

    Snow Leopard 10.6 default boots into 32-bit kernel, but for developers working on 64-bit kernel extensions, Snow Leopard could boot a 64-bit kernel.  This gave developers over 2 years to create 64-bit kernel extensions and drivers.


    Lion 10.7 default boots a 64-bit kernel, but was able to also boot a 32-bit kernel for users that had 32-bit kernel extensions and drivers that had not been updated to 64-bits yet, giving developers another year to create those drivers or the users more time to find a replacement, if the developer was not interested in creating the 64-bit kernel extensions.


    Mountain Lion 10.8 "Always" boots a 64-bit kernel, and as far as I know does not have a 32-bit version.


    You profile says "Mountain Lion 10.8", but the "Categories" line says this is about Snow Leopard 10.6 and your quesiton says Snow Leopard.  I just want to be sure which system you are checking.


    Which system are you checking.  Mountain Lion Applications -> Utilities -> System Profiler does not need to tell you 32 vs 64-bit kernel, since it is always a 64-bit kernel.  Snow Leopard and Lion System Profiler should both tell you if the kernel is booting a 32 or 64-bit kernel.


    You can also check via an Applications -> Utilities -> Terminal session:


    system_profiler | grep -i kernel   # this is from Lion, but Snow Leopard will be similar
    Kernel Version: Darwin 11.4.2
    64-bit Kernel and Extensions: Yes


    NOTE:  Regardless of the flavor kernel booted, Mac OS X will run both 32 and 64 bit apps on any of these platforms.  Actually Mac OS X has been running 64-bit apps on 32-bit kernels since at least Tiger 10.4.


    Can you explain the why you wish to know the flavor kernel running on your system?


    Message was edited by: BobHarris