Will Macbooks run 64 bit kernel

[NewMacbookPlz]

Has anyone with a late 2008 unibody macbook5,1 gotten the 64bit kernel to boot up? I have this computer and nothing seems to be working for me. I've tried holding the 6 and 4 keys, editing the plist, adding arch=86_64 to nvram and using 3 different applications that are supposed to get it to boot in to 64bit kernel. Nothing is working. :<<

You won't see any benefit from it anyways, so quit fretting.

 

[MarkCooz]

This doesn't really mean i'm running on 64 bit am I?

 

[NewMacbookPlz]

This doesn't really mean i'm running on 64 bit am I?

Nope.

Change "My Processes" to "All Processes" and check what "kernel_task" says. As said by me, and many others, it won't make any difference what mode the kernel is in for day-to-day work, as 64-bit applications and extensions are still fully supported. There are numerous reports that the MacBooks cannot even load the 64-bit kernel even with the 64 keystroke while booting, and to be honest, I don't care...SL is running great and does what I need it to, so that's that for me and my UMB.

 

[Daveoc64]

This doesn't really mean i'm running on 64 bit am I?

Assuming you're trying to run it on the MacBook in your signature, no.

In the top right of the "Activity Monitor" window use the drop down that is currently showing "My Processes" and change it to "All Processes".

Then look for the process called "kernel_task". If it's 32-bit (Just saying "Intel"), you have the 32-bit Kernel. If it's 64-bit, you have the 64-bit kernel.

 

[MarkCooz]

Assuming you're trying to run it on the MacBook in your signature, no.

In the top right of the "Activity Monitor" window use the drop down that is currently showing "My Processes" and change it to "All Processes".

Then look for the process called "kernel_task". If it's 32-bit, you have the 32-bit Kernel. If it's 64-bit, you have the 64-bit kernel.

Oh well. that sucks. It doesn't really matter to me... all the matters to me is my bluetooth is acting up upon installing snow.

any suggestion guys...

 

[UnWeave]

The main reason for not enabling a 64-bit kernel is that it requires that all drivers be 64-bit. For Apple's own hardware, this isn't a problem, but there are many 3rd party hardware vendors (printers is a common example) who do not yet have 64-bit drivers. This would prevent many users from using their equipment, and doesn't really fit in with the "it just works" philosophy.

Since a printer is unlikely to be connected to an Xserve system, this is probably why it boots to 64-bit by default. Also, anyone running the server would (you would hope) know about this sort of stuff, and be able to change things accordingly - like booting into 32-bit mode if necessary.

All this aside, so long as you have a 64-bit CPU you WILL be running almost all, if not all, programs in the OS in 64-bit mode and will be able to make use of all 64-bit advantages as a result. The lack of a 64-bit kernel does not stop this in OS X, and a 64-bit kernel is unlikely to make any noticeable difference to performance.

In a nut-shell: 64-bit Intel CPU = AT LEAST 64-bit capable OS with a 32-bit kernel. Don't worry, you're hardly missing out on anything.

For more info, see here and here.

EDIT: This page actually explains it better and more briefly than either of the other two I linked to. It also has a program that will tell you what bit EFI and CPU you have and also (if you have Snow Leopard installed) what version of the kernel you are running - avoids the command line for those of you who don't like using it.

 

[quactaur]

Its probably been dealt with enough times in this thread alone, but yeah, the 64 bit kernel is almost useless at this time. Take a look at Arstechnica's absolutely fantastic (and at times very very technical) review for a good explanation:

The first reason has to do with RAM, and not in the way you might think. Though Leopard uses a 32-bit kernel, Macs running Leopard can contain and use far more RAM than the 4 GB limit the "32-bit" qualifier might seem to imply. But as RAM sizes increase, there's another concern: address space depletion—not for applications, but for the kernel itself.

As a 32-bit process, the kernel itself is limited to a 32-bit (i.e., 4GB) address space. That may not seem like a problem; after all, should the kernel really need more than 4GB of memory to do its job? But remember that part of the kernel's job is to track and manage system memory. The kernel uses a 64-byte structure to track the status of each 4KB page of RAM used on the system.

That's 64 bytes, not kilobytes. It hardly seems like a lot. But now consider a Mac in the not-too-distant future containing 96GB of RAM. (If this sounds ridiculous to you, think of how ridiculous the 8GB of RAM in the Mac I'm typing on right now would have sounded to you five years ago.) Tracking 96GB of RAM requires 1.5GB of kernel address space. Using more than a third of the kernel's address space just to track memory is a pretty uncomfortable situation.

A 64-bit kernel, on the other hand, has a virtually unlimited kernel address space (16 exabytes). K64 is an inevitable necessity, given the rapidly increasing size of system memory. Though you may not need it today on the desktop, it's already common for servers to have double-digit gigabytes of RAM installed.

The other thing K64 has going for it is speed. The x86 instruction set architecture has had a bit of a tortured history. When designing the x86-64 64-bit extension of the x86 architecture, AMD took the opportunity to leave behind some of the ugliness of the past and include more modern features: more registers, new addressing modes, non-stack-based floating point capabilities, etc. K64 reaps these benefits. Apple makes the following claims about its performance:

•250% faster system call entry point
•70% faster user/kernel memory copy
Focused benchmarking would bear these out, I'm sure. But in daily use, you're unlikely to be able to attribute any particular performance boost to the kernel. Think of K64 as removing bottlenecks from the few (usually server-based) applications that actually do exercise these aspects of the kernel heavily.

If it makes you feel better to know that your kernel is operating more efficiently, and that, were you to actually have 96GB of RAM installed, you would not risk starving the kernel of address space, and if you don't have any 32-bit drivers that you absolutely need to use, then by all means, boot into the 64-bit kernel.

From that it is quite curious (I do believe an AMD64 dev posted on here about it) that the main (only) benefits of the 64 bit kernel has more to be with AMD streamlining and improving the x86 instruction set than actually being 64 bit.


Full review in its 20+ page glory here:
http://arstechnica.com/apple/reviews/2009/08/mac-os-x-10-6.ars/5

 

[Tshapi]

64 bit kernal

if you did your homework, you would see that 64bit is disabled simply because the macbook is a consumer computer and not pro. apple is setting 64bit up as a distinction between consumer and pro electronics.

 

[ssn637]

Unibody MacBook Snow Leopard 64-bit Kernel

I was also able to unlock the 64-bit Kernel restriction on the Unibody MacBooks by following the instructions given in this blog:

http://netkas.org/?p=189#comments

I had to make some adjustments to the original instructions (see my feedback comments) to prevent the system from defaulting back to a 32-bit startup kernel. Although I was overjoyed at being able to start up in 64-bit kernel mode, the system again locked up when I tried surfing with 8 GB RAM installed. Some users had reported that their late '08 MacBook Pros were 8 GB RAM capable in 64-bit mode, but this doesn't seem to be the case with the Unibody MacBooks.

 

[DMiro]

I did!!! - Macbook Generation 6 (Late 2008) 64bit Kernel Mode

According to this post, booting into a 64-bit kernel in Snow Leopard on the ‘original’ 13″ Unibody MacBook is artificially crippled by Apple, despite the hardware being perfectly capable:

$ ioreg -p IODeviceTree -w0 -l | grep firmware-abi
| | "firmware-abi" = <"EFI64">

This is somewhat annoying given that I’m a proud owner of said machine. Why bother, you might ask? Is it worth it? Well that’s up to you, but significant performance increases have been reported especially in applications like Lightroom and Photoshop, so for me it’s worthwhile.

Anyway, the trick – as that article describes – is to modify the list of 64-bit capable models in boot.efi, and it’s more straightforward than you might think.

Firstly you’ll need to download an application called HexEdit, and then copy the boot.efi file somewhere for editing:

$ sudo cp /System/Library/CoreServices/boot.efi ~/Desktop/

Fire up HexEdit, and then open up the boot.efi file on your desktop. Select Find / Go To Address from the menubar, and enter 0x266E8 as the address to jump to. You’ll see the following:

0x266E0: 38 47 01 00 00 00 00 00 00 00 00 00 00 00 00 00

Amend this to say:

0x266E0: 38 47 01 00 00 00 00 00 04 00 00 00 00 00 00 00

Be careful that you overwrite those values, and not accidentally insert. Save the file, go back to the terminal and enter the following commands:

$ cd /System/Library/CoreServices
$ sudo chflags nouchg boot.efi
$ sudo cp boot.efi boot.efi.old
$ sudo cp ~/Desktop/boot.efi .
$ sudo chown root:wheel boot.efi
$ sudo chflags uchg boot.efi
$ sudo bless --folder /System/Library/CoreServices --file /System/Library/CoreServices/boot.efi

Note that we took a copy of the original boot.efi, just in case things happen to go awry. You’ll also need to tell SL to boot the 64bit kernel by default, so do the following:

$ sudo vi /Library/Preferences/SystemConfiguration/com.apple.Boot.plist

And amend the Kernel Flags to read:

<key>Kernel Flags</key>
<string>arch=x86_64</string>

This will make your change to a 64-bit kernel the default. If you wish to revert to the 32-bit kernel, press and hold 32 on the keyboard as your computer boots.

 

[Graeme43]

I managed to get my Nov 2006 C2D Macbook to boot into 64 bit mode (It says 64-bit Kernel and Extensions: Yes) and only shows 64 bit extensions. However it has the GMA950 and its stuck at 1024x768 it was an accident really I was messing around with stuff and it worked. GMA950 + Airport driver are 32 bit so its useless really lol

 

[Bengt77]

What happens if you actually do get the 64-bit kernel running and you start a 32-bit application? Will it run? Will it try to run but crash? Will it refuse to run altogether? What will happen?

 

[Graeme43]

I only tried skype & mail, its pointless running like that as display wont run native and i cant use airport

 

[Giuly]

I only tried skype & mail, its pointless running like that as display wont run native and i cant use airport

edit your /Library/Preferences/SystemConfiguration/com.apple.Boot.plist and put in

<key>Graphics Mode</key>
<string>1280x800</string>

between the <dict> and </dict>. Adjust the setting to your native resolution. Easiest way to fix the AirPort problem is installing a newer 802.11n one - or if you're running 10.6.1, hit the update.

Regards

 

[Graeme43]

The broadcom airport card has 64 bit kext, my macbook has the atheros one though, anyone know what the newest Macs ship with?

Architectures: i386, x86_64
64-Bit (Intel): Yes
Location: /System/Library/Extensions/IO80211Family.kext/Contents/PlugIns/AppleAirPortBrcm4311.kext

 

[blackburn]

 

[Graeme43]

/me claps my Mac Pro HD4870

 

[Giuly]

Now this really sucks. I guess I need to edit another part of the boot.efi?

Regards

 

[blackburn]

I don't really think that macminis need to have ther boot.efi edited for 64bits.. And if it's the latest one I think you only need to do the plist thing.

com.apple.Boot.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>Kernel</key>
	<string>mach_kernel</string>
	<key>Kernel Flags</key>
	<string>arch=x86_64</string>
</dict>
</plist>

 

[Giuly]

Booting up with holding "6" and "4" keys on the keyboard or modifying /Library/Preferences/SystemConfiguration/com.apple.Boot.plist does the trick:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
        <key>Kernel Flags</key>
        <string>arch=x86_64</string>
</dict>
</plist>

I just blew the top score