32- or 64-bit Kernel Startup Mode Selector... Mac OS X 10.6 Snow Leopard is 64-bit - or is it?
Well, actually Mac OS X 10.6 Snow Leopard is both 32-bit and 64-bit, and what that means for you depends on both your hardware and your settings.
I put Up an accompanying website which should answer most of your questions
here.
What does this app do?
it shows whether you have a 32-bit or a 64-bit processor
it shows whether you have a 32-bit or a 64-bit EFI
it shows whether the MacOS X Kernel is set to boot in 32-bit or in 64-bit mode
it shows whether the MacOS X Kernel is running in 32-bit or in 64-bit mode
it shows whether Apple officially supports booting a 64-bit kernel on your Mac
it allows you to select whether you want to start the MacOS X Kernel in 32-bit or in 64-bit mode (the setting might be ignored on MacBooks, depending on how Apple implements the restriction)
accompanying webpage explains what the whole commotion about 32-bit and 64-bit in MacOS X Snow Leopard is about
Requirements:
To check your configuration:
Intel Mac
Mac OS X 10.4 Tiger or higher
To set the kernel's startup mode:
Intel Mac
Mac OS X 10.6 Snow Leopard or higher
Admin rights (as a system file needs changing)
WHAT'S NEW
Version 1.3.3
NEW: added feedback window when unknown Mac is encountered
added info for MacBookPro5,4
improved feedback window
resolved issue when no boot mode was set
NEW: added info on new models
NEW: added icons for unknown and capable but not supported models
NEW: made some helptext model specific
NEW: shows Mac model