Comments on: Force Snow Leopard to Use 64 Bit Kernel

By: Mike

Mike — Tue, 20 Dec 2011 16:00:42 +0000

Hi, I have a late 2009 iMac, 12 GB ram , 3.06Ghz cpu , 9400M GPU.
Booted with 32bit kernel , and the results are :

Lightroom export 50 RAW files 5:06 sec
Photoshop filter: 00:12 sec
Photoshop surface blur: 26 sec

in 64-bit kernel result are :

Lightroom export 50 (same files) 5:16 sec
Photoshop filter (same filter same file) 00:16 sec
Photoshop surface blur: 28 sec ..

how do you explain that ?

By: Terry J Fundak

Terry J Fundak — Thu, 14 Jul 2011 18:43:45 +0000

What version of VMWare Fusion was this?

I currently have FUsion 3.1.3 and I’m trying to Beta Lion Server as a client of Fusion and I’m wondering if this is possible because the “app” VMWare Fusion appears to be 32 bit…..but I can’t tell at what level of the software stack I need 64 bit to upgrade a Snow Leopard Server VM to a Lion VM.

By: Al Sargent

Al Sargent — Sun, 23 Jan 2011 17:56:11 +0000

One reason: For some developers, 64 bit is a requirement if you’re working with large datasets.

By: Macbook Pro, warto? Potrzebuję ciekawych argumentów ZA i PRZECIW :)

Macbook Pro, warto? Potrzebuję ciekawych argumentów ZA i PRZECIW :) — Thu, 25 Nov 2010 21:07:45 +0000

[...] nie widze jej w watku… Dziekuje za wklad, bede sledzil watek! Pozdrawiam, Cyrylski Force Snow Leopard to Use 64 Bit Kernel Z przełączaniem aplikacji jest jeszcze prościej [...]

By: Howard

Howard — Sat, 26 Jun 2010 13:24:07 +0000

AG, you are wrong. I am typing this on a MacBook Pro and it is running 64-bit, as invoked with the 6,4 keys and as confirmed by checking “about this Mac”.

By: Alex

Alex — Fri, 14 May 2010 02:34:43 +0000

I use the plist editor with the dev tools, backed up the old one, altered it and put replaced the old one. I used the method noted by MKF for to change the com.apple.Boot.plist, it was the only method that worked for me on my MBP 5,5

By: Stuart

Stuart — Wed, 09 Dec 2009 20:05:37 +0000

So what’s the whole hype with using 64-bit anyways? I heard something about how Safari 4 in 64-bit executes JavaScript 50 times faster. 64-bit sounds nice if you have more than 4GB of RAM other than that what’s with using all this powerful computing power?

By: Brandon

Brandon — Sun, 06 Dec 2009 21:12:06 +0000

Your computer will only support 64bit booting if your processor does. Core Duos are NOT 64-bit compatible, but Core 2 Duos are. Xeons are, as well. That’s why some of you cannot boot in 64bit mode.

By: Aaron

Aaron — Mon, 16 Nov 2009 04:40:31 +0000

my dual action logitech game pad didnt work right under the 64bit kernel. So I rebooted back to 32. Works fine. I dont seem to notice anything different under 64bit kernel mode.

By: MKF

MKF — Wed, 14 Oct 2009 06:20:32 +0000

My Mac Pro (8 Core Xeon) did not boot in to 64 bit mode and I need to edit file;

/Library/Preferences/SystemConfiguration/com.apple.Boot.plist

…and change last string. Like below.

Kernel
mach_kernel
Kernel Flags
arch=x86_64

Now my Mac runs in 64 bit mode and all benchmark programs give 1.2-1.5x better scores.

Sadly, I need to switch back to 32 bit mode, bcs VMWare Fusion is not yet 64 bit. But it will (27-oct-2009 comes out 64 bit VMWare Fusion. Great!).

By: arce

arce — Tue, 06 Oct 2009 18:40:16 +0000

i got this;
uname -a
Darwin xarcex 10.0.0 Darwin Kernel Version 10.0.0: Fri Jul 31 22:47:34 PDT 2009; root:xnu-1456.1.25~1/RELEASE_I386 i386

so what’s my kernel?

By: Bruno

Bruno — Fri, 02 Oct 2009 05:52:19 +0000

To change mode 32 to 64 bits on snowleopard client, you’ve to do that: Write sudo nvram boot-args=”arch=x86_64″ on console.
After reboot, for checking that: write uname -a on console against and you are showing: Darwin macbook_pro.home 10.0.0 Darwin Kernel Version 10.0.0: Fri Jul 31 22:46:25 PDT 2009; root:xnu-1456.1.25~1/RELEASE_X86_64 x86_64.
Now, you use the Kernel Boot x64.

By: Justin

Justin — Mon, 21 Sep 2009 04:39:49 +0000

I’ve got the ’08 MacBook 2.4 (MacBook5,1)
And with the quick hack provided by http://www.osxbook.com/blog/2009/08/31/is-your-machine-good-enough-for-snow-leopard-k64/ I’m up and running with the 64 bit kernel.

Although it doesn’t really buy me anything it’s neat nonetheless

By: DistortedLoop

DistortedLoop — Sun, 20 Sep 2009 15:13:09 +0000

@Nigel – “The initial startup into 64 bit is slow, but afterwards it’s great.”

Just curious, what’s great about it? Does the system run faster? Have you benchmarked it (timed apps opening in 32 vs 64 bit mode), or do you just “feel” it’s great? Is it more stable? Fewer beach balls? What?

Thanks.

By: Greg

Greg — Sun, 20 Sep 2009 05:55:36 +0000

You can enter a line in Terminal that will make it always boot up into 64 bit:
sudo nvram boot-args=”arch=x86_64″
sets it to always boot 64 bit.

You should be able to reset things as follows:
sudo nvram boot-args=”"