Enabling 64-Bit in Snow Leopard
The most powerful update in Snow Leopard is the ability to move to 64-bit support. By default, Snow Leopard has 32-bit enabled and you have to purposefully enable 64-bit.
Here is how to determine if you have 64-bit enabled.
- Start the Systems Profiler through the Applications or Click the on the Apple Menu and choose About This Mac > More Info
- Highlight “Software”
- Look to see if the “64-bit Kernel and Extensions” has a Yes or a No to identify whether 64-bit is enabled.
Enable: To enable 64-bit you have to hold down the 4 and 6 on the keyboard when you boot up the computer. Check back in the Systems Profiler and it should be marked as yes.
I am not sure if they will turn this into an official setting some place, but here is how to enable 64-bit by default on startup. Huge thanks to netkas.org who originally posted these settings.
Long Term Enable:
Find this file…
/Library/Preferences/SystemConfiguration/com.apple.Boot.plist
In that file, find the lines that read:
<key>Kernel Flags</key>
<string></string>
and change them to
<key>Kernel Flags</key>
<string>arch=x86_64</string>
Tried holding down “64″ at start up-no luck; System Profiler still reported “No”.
Next tried editing the Boot; had to change permissions; tried to save and was told that the file could not be saved.
?
@Tad
I am not sure when the timing of holding the keys is important. I pressed them shortly after hearing the boot tone and held out there until after the apple screen went away.
As far as editing the file, you need to have superuser access, in order to modify files that will affect the boot record. You can do some searches on how to enable superuser access. Here is what I do for reference. Some people do not feel comfortable working at the command line level.
I open a Terminal session from Applications. Then I use the sudo command to invoke superuser permissions to open a shell session in that terminal. Finally I use pico to edit the file.
Applications -> Terminal
sudo -s
type in your password
pico /Library/Preferences/SystemConfiguration/com.apple.Boot.plist
edit the file
Control-X to exit with prompting to save.
Hope this helps.
Stephen
Tried the 4 and 6 keystroke combination – no luck
Edited the com.apple.Boot.plist file – no luck
verified the Mac is 64 bit compliant hardware wise with sysctl hw | grep 64bit
Reviewing the status in Profiler for software, still shows no for 64 bit and extensions.
Is there another step I can try?
Thanks.
Check to see what processor you have. Despite the software checks, really only the more recent Intel based Macs carrying the Intel Core 2 Duo chips are actually 64 bit. Those and the Xeon processors, which may have only been in the server line. All of the previous generations have not been 64 bit.
If you do have a newer machine with Intel Core 2 Duo, then there is no real reason it is not working.
Stephen
Stephen
It works. Thanks for the article, nice to know my Macbook Pro is running in 64Bit mode permanently. Now we just need the likes of iTunes to be in 64Bit