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MacBookPro3,1 + 10.6.8 + EFI64 = still no 64bit kernel?

Model Name: MacBook Pro

Model Identifier: MacBookPro3,1

Processor Name: Intel Core 2 Duo

Processor Speed: 2.4 GHz

Number Of Processors: 1

Total Number Of Cores: 2

L2 Cache: 4 MB

Memory: 8 GB

Bus Speed: 800 MHz

Boot ROM Version: MBP31.0070.B07

SMC Version (system): 1.18f5



Hello,


I know this has been asked numerous times, but most of the answers I found were old and archived. I was wondering whether or not an update or a guide has been released which allows a successful boot into 64bit kernel?


On a side note, I have verified my computer does have EFI64. However I know in the past that this stil didn't enable a 64bit boot.


Thank you in advance for any and all replies 🙂.

MacBook Pro, Mac OS X (10.6.8)

Posted on May 18, 2012 10:02 PM

Reply
11 replies

May 18, 2012 11:06 PM in response to Damainman

Open terminal (in Utilities), and copy/paste the following line:


uname -a


If you see something like "RELEASE_I386 i386" at the end of the string you are running a 32-bit kernel.


Macbook pro 3,1 is a late 2007 model which does not support running 64-bit mode.


Mac OS X v10.6: Macs that use the 64-bit kernel


Mac OS X: 64-bit kernel frequently asked questions

May 19, 2012 12:11 AM in response to X423424X

Thank you for the reply. I was hoping that Apple decided to release an update I didn't know about that would enable the 64bit kernal considering I have a 64bit processor, 10.6, and the 64bit firmware(EFI64). Had my fingers crossed and you crushed my dreams lol.


Apple says my Mac is only capable of 4GB of memory, but I am successfully running 8GB with no issues and was hoping they were wrong about the 64bit kernal as well.


If no other replies enable me to boot into 64bit kernel then I will mark yours as my answer.

Jun 18, 2012 9:21 AM in response to Damainman

You may be in luck, but it will cost $25 for an update to Lion (or $20 for Mountain Lion).


My MBP 3,1 would only boot into 32 bit kernel under 10.6 Snow Leopard, but under 10.7 Lion it will boot sucessfully into 64 bit kernel. It does not appear to be common knowledge.

http://forums.macrumors.com/showthread.php?p=15070396


I would be interested to hear whether a Lion/Mountain Lion upgrade (thus enabling 64bit EFI+kernel) would allow your machine to address the full 8GB of memory rather than the first 4 or 6GB (depending on who you listen to). I only have 4GB.


Hope this helps.

Jun 18, 2012 11:08 AM in response to Damainman

There isn't a way to make that Mac boot to a 64 bit kernel. We're using an iMac from the same era, also a Core 2 Duo. Even running Lion on it (the Server version) it will not, and cannot be made to boot to a 64 bit kernel.


Unless you have a very specific need for a 64 bit kernel, you aren't really missing much. 64 bit apps will still run 64 bit under a 32 bit kernel. If you check in the System Profiler under the software heading, you'll see that every part of OS X is running 64 bit. Everything but the kernel itself, that is.

Jun 18, 2012 12:11 PM in response to Kurt Lang

@Kurt,


Can't speak for your iMac, but a Mid-2007 17" MacBookPro 3,1 2.4Ghz Santa Rosa would not run 64bit kernel under 10.6 Snow Leopard but does so under 10.7 Lion. The Lion was built from a clean install.


You are correct in that it was never supported on a MacBook Pro 3,1 under 10.6. http://support.apple.com/kb/HT3770 but that page is specific to 10.6 Snow Leopard. Apple have not updated the support page for 10.7 Lion.


Seems to work for others as well.

http://forums.macresource.com/read.php?1,1339909,1339965

http://forums.macrumors.com/showthread.php?p=15070396


Sorry to hear that it doesn't work for your iMac of the same era, but that does not necessarily translate to the original poster's Macbook Pro 3,1. Although your system is of the same age as a MacBook Pro 3,1, the EFIs may differ between the models http://support.apple.com/kb/HT1237 or perhaps the graphics drivers differ significantly? I'm afraid I can't speak with any authority about your iMac system, but it certainly works on the MBP3,1 under Lion.

Nov 30, 2012 6:16 AM in response to Damainman

I know that this is an old post, but I didn't see anyone mention it here so I figured I'd pipe in as well.


This wouldn't be a permanent fix, and it would reset after you shutdown or restart your computer.


If you look into "about this Mac" and click on more info and select "software" on the list. You should see an option that says 64-bit Kernel and Extensions. If it says no, then you are currently in 32-bit mode. If yes, then you are in 64-bit mode.


To start up in 64-bit mode (if your Mac supports it which Intel Core 2 Duo does), start your computer and hold Command + Option + 6 + 4 (like you would if you were resetting the PRAM). That's it. You should now be in 64 bit mode. Check about this Mac again to see if it switched.

Mar 3, 2013 1:17 PM in response to ejekabsons

I too would welcome the experiences of anyone running 8GB(2x4GB) in a MacbookPro 3,1 under Lion/Mountain Lion.

  • Apple never officially supported anything other than 4GB(2x2GB) for this model
  • Many years ago, Other World Computing ran full tests and determined that 6GB(2+4GB) was the unofficial maximum for this model
  • 8GB(2x4GB) was reported to be unreliable under OS X 10.6 Snow Leopard on this model. It was generally considered to be the EFI that stopped 8GB RAM from working reliably.


With the launch of Lion, Apple did silently upgrade the EFI to support full 64bit EFI/Kernel on the MacBook Pro 3,1. Under Mountain Lion, the Macbook Pro 3,1 even boots into full 64bit EFI/Kernel by default. Very few of the articles or threads about the MacBook Pro 3,1 acknowledge this undocumented change.


Markus Winter's 'Startup Mode Selector' is a useful way to confirm the new 64 bit EFI/Kernel support under Lion/Mountain Lion. Otherwise…


MacBookPro17:~$ ioreg -l | awk '/product-name/ { split($0, line, "\""); printf("%s\n", line[4]); }'

MacBookPro3,1

MacBookPro17:~$ ioreg -l -p IODeviceTree | grep firmware-abi

| | "firmware-abi" = <"EFI64">

MacBookPro17:~$ uname -a

Darwin MacBookPro17 12.3.0 Darwin Kernel Version 12.3.0: Sun Jan 6 22:37:10 PST 2013; root:xnu-2050.22.13~1/RELEASE_X86_64 x86_64


I do hope that since the EFI has changed to support full 64bit that it may also now reliably support 8GB.


Anyone out there with 8GB on a MacBook Pro 3,1? Unfortunatly, 4GB DDR2-667 PC2-5300 modules are still quite expensive.

Mar 4, 2013 9:47 AM in response to ejekabsons

Apologies. Poor assumption on my part. The full 64bit EFI/Kernel statement still stands though.


With the launch of Lion, Apple did silently upgrade the EFI 'something' to support full 64bit EFI/Kernel on the MacBook Pro 3,1. Under Mountain Lion, the Macbook Pro 3,1 even boots into full 64bit EFI/Kernel by default. Very few of the articles or threads about the MacBook Pro 3,1 acknowledge this undocumented change.


I do hope that since the EFI 'something' has changed to support full 64bit that it may also now reliably support 8GB. It is not unknown for Apple to make quiet fixes to address all 8GB memory. They did so on the MacBook Pro 5,1 http://blog.macsales.com/9102-secret-firmware-lets-late-08-macbooks-use-8gb, in this case a combo of EFI and a minor release of the OS.

MacBookPro3,1 + 10.6.8 + EFI64 = still no 64bit kernel?

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