Have just upgraded memory to 4GB and just found out that the Intel Core 2 Duo is 64 bit, I want to know whether my system running in 32 or 64 bit.
By default Snow Leopard run in 32 bit but can be changed to 64 by hitting “6” and “4” while booting. This is the result before:
After I boot and hold “6” and “4” keys, nothing’s changed. Why?
Because the EFI is still 32-bit, so my system cannot run 64-bit kernel. Oh well.
More about this here: