A friend told me today that Apples new operating system Snow Leopard (MacOS X 10.6) is not running a 64bit kernel as Apples massive marketing campaign might suggest.
In fact most of the desktop Macs are running the 32bit kernel by default. Only the Apple Xserve with proper CPUs will run the 64bit kernel by default.
The cause of that seems to be the fact that a lot of the drivers were not finished as 64bit version when Snow Leopard was ready. So Apple decided to deliver both kernels and boot the 32bit by default on the desktops.
However you can explicitly choose the 64bit kernel during boot by pressing the keys “6” and “4”. You can tell that you’re running the 64bit kernel by entering the following command in your Terminal:
It should look like this:
Darwin voyager.alice-dsl.de 10.0.0 Darwin Kernel Version 10.0.0: Fri Jul 31 22:46:25 PDT 2009; root:xnu-1456.1.25~1/RELEASE_X86_64 x86_64
The important part is the “x86_64″. It would be “i386″ if it’s the 32bit kernel.