how to set a MAC Pro permanently into 64 bit mode
Open Applications/Utilities/Terminal
type in the following:
sudo nvram boot-args="arch=x86_64"
quit the Terminal Application, and reboot your computer.
It will now be in 64 bit mode
Open Applications/Utilities/Terminal
type in the following:
sudo nvram boot-args="arch=x86_64"
quit the Terminal Application, and reboot your computer.
It will now be in 64 bit mode