Saturday, August 29, 2009

13" Mac laptop and 64-bit Snow Leopard: It works!

13" Mac laptop and 64-bit Snow Leopard: It works! Well, sorta. I can confirm it works on the latest 13" MacBook Pro at least.

Whether your Mac's CPU is 64-bit or not, Mac OS X 10.6 Snow Leopard's 64-bit kernel is normally only able to load if the machine also has a 64-bit EFI. You can tell if your machine has a 32-bit or 64-bit EFI by typing this command in Terminal:

ioreg -l -p IODeviceTree | grep firmware-abi

However, according to OSnews, the OS X seed notes claim that the 64-bit kernel of Snow Leopard is not supported on any 13" Mac laptop, even if it has a 64-bit EFI. Despite this, 64-bit Snow Leopard loads on my 13" MacBook Pro (aka MacBookPro5,5) just fine.

The latest 13" Mac lives up to its "Pro" name after all.

Despite having this 64-bit capability, I will usually run in 32-bit mode since 32-bit kernel extensions (like printer drivers, etc.) won't run when the 64-bit OS X kernel is loaded, and 64-bit applications can still run normally with the 32-bit OS X kernel.


Surendar Chandra said...

How did you manage that (I tried the 6+4 key and that didn't work)

Eug said...

Well, I have the latest 13" MacBook Pro. This machine was released just a couple of months ago, and is the first 13" MacBook to be labelled as "Pro".

Surendar Chandra said...

I have the same one except I can't go to 64 bit mode.

System Version: Mac OS X 10.6 (10A432)
Kernel Version: Darwin 10.0.0
Boot Volume: HD
Boot Mode: Normal
Computer Name: SMac
User Name: Surendar Chandra (surendar)
Secure Virtual Memory: Enabled
64-bit Kernel and Extensions: No
Time since boot: 19 minutes

Eug said...

Hmmm... That's strange, Surendar. FWIW, immediately after I turn on the machine, I press the 6 and 4 keys and hold them for quite some time before letting go, making sure Snow Leopard is well into the boot process. However, if that still doesn't work, you could also try modifying your file:

I have not tried this method myself though. Try it at your own risk.

Also, if it helps, here are my machine's specs:

Model Name: MacBook Pro
Model Identifier: MacBookPro5,5
Processor Name: Intel Core 2 Duo
Processor Speed: 2.26 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 3 MB
Memory: 2 GB
Bus Speed: 1.07 GHz
Boot ROM Version: MBP55.00AC.B03
SMC Version (system): 1.47f2

yankcrime said...

You can get it to work on the 13" Unibody non-Pro, but it requires a little bit of hacking:

jcakashiya said...

I have the same MBP and have no problem getting it to 64bit.

The problem I am getting is installing win7 64 via bootcamp.

Once win7 installer loads up it says unable to load device driver.... bummer.

jcakashiya said...

If you guys have a solution, do share with me.


First Last said...

I'm currently running 10.6.8 on my 13" Macbook (MB063LL/B - Santa Rosa)

Model Name: MacBook
Model Identifier: MacBook3,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.2 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 4 MB
Memory: 1 GB
Bus Speed: 800 MHz

Installed 10.6 from USB, upgraded the usual way. Without a hitch.