How To: Force Snow Leopard to start in 64bit mode

This is a trick I’ve been doing for a while.  The boring way to start Leopard in a particular mode is immediately after turning the computer on hold down:

3 and 2 – Boot into 32 bit mode; or

6 and 4 – Boot into 64 but mode.

Because Snow Leopard boots into 32 bit mode by default, if you want to have it boot into 64 bit mode all the time, it gets a little tedious remembering to hold down the 6 and 4 key.  Luckily, you can force Snow Leopard to boot into 64 bit mode all the time by editing a particular file.

  1. Open Terminal and type in the following command:
  2. sudo nano /Library/Preferences/SystemConfiguration/
  3. It will ask for your password; enter it.
  4. There should be something that looks like this:  <key>Kernel</key>
    <key>Kernel Flags</key>
  5. After the “Kernel Flags” change the <string> value to arch=x86_64.  It should look like this:
  6. <key>Kernel</key>
    <key>Kernel Flags</key>
  7. Save by hitting “Control O”  (And then enter)
  8. Exit by hitting “Control x”
  9. That’s it, you’re done!

I must note that not all computers can boot into 64 bit mode, so make sure your computer can.  To check what mode you are in, go back to the terminal and type :  uname -a

If you are in 32 bit mode, you’ll see many “i386.”  If you see “x86_64” then you are running in 64 bit mode.

If you fuck up your Mac, it’s not my fault.


~ by wayfarer247 on October 9, 2009.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: