How To: Boot into 64-Bit Mode by Default

Straight out of the box, Snow Leopard is one cool OS.  BUT... by default, you're only running in 32-bit mode.  Sure, you could hold down "6" & "4" at boot until you see the little spinning gear but that can be a pain if you reboot regularly or if you have a MacBook and are constantly on the go.  It's also a real pisser when you forget and have to power down again and go through the whole process a second time.  That's where this little tip comes in handy.

In order to enable 64-bit mode by default,  navigate the the following folder:

/Library/Preferences/SystemConfiguration/

Now edit the file "com.apple.Boot.plist" in TextEditor.

Search for the lines that read:

<key>Kernel Flags</key>
<string></string>

Between the STRING flags, add the following:

arch=x86_64

Save, reboot and never worry about missing that 5 second window to activate 64-bit mode ever again.


BTW - you may need to modify permissions on the file and folder it resides in to be able to save the file.