Boot your snowy cat in 64-Bit

Apple is advertising with the feature of its 64-Bit capability. More surprising is that 64-apps can be run bei Snow Leopard but the OS itself boots in 32-Bit on all Mac computer by default except of the latest XServes computer.


But you are able to switch the boot mode of 32-Bit to 64-Bit. Here are several ways how you can change that setting:


1.) If you want to boot in 64-Bit, press and hold the keys "6" and "4" during the boot; otherwise if you want to boot in 32-Bit press and hold "3" and "2". That's pretty simple.


2.) Edit the configfile: /Library/Preferences/SystemConfiguration/com.apple.Boot.plist and add the value arch=x86_64 to Kernel Flags:



Kernel
mach_kernel
Kernel Flags
arch=x86_64


At the next boottime your kernel will boot in 64-Bit. Just replace x86_64 with i386. 


Caution: Do this only if you know what you do!


3.) Make the setting permanently with the command:


 nvram bootargs="arch=x86_64"


with nvram -d bootargs you can switch back to the default 32-Bit boot mode.




Have you already collected any experience with the performance? If yes, write it down! Thx :)