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nando
28th August 2009, 04:44 PM
according to this article Will your Mac boot 64-bit Snow Leopard by default? Not unless it's an Xserve | The Apple Core | ZDNet.com (http://blogs.zdnet.com/Apple/?p=4712)
snow leopard will not boot in 64 bit by default.
in essence it says

OS News reports that some Macs with 64-bit processors won’t be able to load the 64-bit kernel because they have a 32-bit EFI. The seed notes explain which Macs can boot into a 64-bit kernel and drivers by default (Xserve), and which ones are only “capable” — meaning you have to hold down the 6 and 4 keys at boot.
Still not sure if your Mac has the 32 or 64-bit EFI? You can check your machine’s it by entering the following command in Terminal:

ioreg -l -p IODeviceTree | grep firmware-abi
It will return either “EFI32″ or “EFI64.”

BTW mine returned as EFI64 and didnt do any key thing....

u98925
28th August 2009, 05:18 PM
My Mac Pro returns "EFI32"

Rebooted and held the 6 and 4 kesy down and cant see any change yet....

Huy
28th August 2009, 05:24 PM
My Mac Pro returns "EFI32"

Rebooted and held the 6 and 4 kesy down and cant see any change yet....

Look in System Profiler > Software

Under '64-bit Kernel and Extensions' of 'System Software Overview' it should say Yes or No. Typically no.

You have a 32-bit EFI.

Jaymz
28th August 2009, 05:43 PM
From the betas, the only models that allowed booting into a 64-bit kernel were the following:


MacPro3,1
Xserve2,1
MacBookPro4,1
iMac8,1
MacBookPro5,1
MacBookPro5,2
MacPro4,1
iMac9,1
Xserve3,1

Not sure if that's indicative of what the retail release supports, but the "golden master" build was restricted to that list as well. That list is essentially every Mac Pro, Xserve, iMac, and 15"/17" MacBook Pro since January 2008. That means owners of the Mac mini, Macbook, Macbook Air, and the 13" Macbook Pro are all out of luck.

Keep in mind that running the 32-bit kernel doesn't affect the ability to run 64-bit applications. If you look at Activity Monitor, you'll still see that most processes are still 64-bit. However, running the 64-bit kernel means you need to load 64-bit kexts - making Snow Leopard a *LOT* more incompatible with anything that needs a third party kext (some types of hardware, for example).

Moral of the story? Relax, already. Chances are, it's not going to make that much of an impact. You still get all that 64-bitness, without the compatibility issues that Windows users had to cop with their first iterations of 64-bit support.

Keljian
28th August 2009, 08:26 PM
I have a mbp 5,1.

I was running the 32 bit kernel after SL install.

I changed a setting in /Library/Preferences/SystemConfiguration/com.apple.Boot.plist

As per here: netkas.org SnowLeopard and 64-bit. (http://netkas.org/?p=127)

There is an easier way here:
Startup Mode Selector (http://www.ahatfullofsky.comuv.com/English/Programs/SMS/SMS.html)

I am now running a 64 bit kernel

spuds_imac
28th August 2009, 08:58 PM
Does it seem any quicker in 64bit mode?

nando
28th August 2009, 09:03 PM
well......doesnt it mean that in 64 bit mode...any application can access double as much at a given time than if it was under 32 bit??
my MBP seems quicker..Google Earth feels snappier..lots of things respond fast...
is like my MBP has a new life!...
A month ago i only had 2GB of Ram...then i updated to 4GB and well...didnt feel as snappier as it is now..

Keljian
28th August 2009, 09:08 PM
Don't know.. didn't play with 32 bit mode long enough to find out.. Just works *shrugs* - I don't use much 3rd party hardware.

HumanMedia
28th August 2009, 09:21 PM
I made sure I weeded out all the 32 bit 3rd party Control Panels (Flip4Mac, Growl, iConnect etc) and rebooted in 64bit mode.

Processor-wise the system iruns about 10% faster on my early 2009 MacPro in 64bit. Quite a surprise as I was led to believe 64bit is generally slower. This is probably due to the processor optimisations for 64bit particular to the latest MacPro processors. However MacBench reports the disk performance to be slower in 64bit...

Im staying in the 64bit dimension for a wile and will report back.

mjankor
28th August 2009, 09:40 PM
If I'm not mistaken where you should see huge speed boosts is when you are dealing with very large numbers. Crunching numbers that may require several passes in 32 bit can be done once in 64 bit.

Rjat
28th August 2009, 09:53 PM
64 bit - meh

ChrisR_12
28th August 2009, 09:56 PM
Hello,

Yea Apple says its 10.6 is 64bit but when you look at it this why its not true 64bit when using the 32bit kernel right?

They may change this with in 10.6.x maybe.

benerrol
28th August 2009, 11:00 PM
Mine (iMac 8,1) booted straight into 64Bit after snow leopard installation.

Huy
28th August 2009, 11:02 PM
They may change this with in 10.6.x maybe.

I don't think 10.6.x is going to change the kernel to 64-bit.

Read this:
What's "64-bit" on Snow Leopard? | Mac OS X | MacUser | Macworld (http://www.macworld.com/article/142379/2009/08/snow_leopard_64_bit.html)

leoleakey
28th August 2009, 11:03 PM
Look in System Profiler > Software

Under '64-bit Kernel and Extensions' of 'System Software Overview' it should say Yes or No. Typically no.

You have a 32-bit EFI.

my says no, but the terminal back with "firmware-abi" = <"EFI64">

Huy
28th August 2009, 11:04 PM
my says no, but the terminal back with "firmware-abi" = <"EFI64">

If you don't have one of those machines mentioned by Jaymz then it'll always say no.

leoleakey
28th August 2009, 11:18 PM
If you don't have one of those machines mentioned by Jaymz then it'll always say no.

mine is MacBookPro5,3

Huy
28th August 2009, 11:20 PM
mine is MacBookPro5,3

It's Mid 2009. That does 64-bit kernel.

leoleakey
28th August 2009, 11:27 PM
It's Mid 2009. That does 64-bit kernel.
how to modify it?

Huy
28th August 2009, 11:28 PM
how to modify it?

Hold 6 and 4 keys at boot to enable 64-bit Snow Leopard (Updated) | The Apple Core | ZDNet.com (http://blogs.zdnet.com/Apple/?p=4716)

leoleakey
28th August 2009, 11:32 PM
thanks huy

pengu
29th August 2009, 01:17 AM
If someone hadn't told you SL uses a 32bit kernel by default, you'd never have known. Having a 32bit kernel doesn't affect your ability to use 64bit software, it just means you aren't restricted to only KEXTs that have been compiled for 64bit.

As for the person who said "it feels snappier in 64bit mode". Look up this word: placebo.

HumanMedia
29th August 2009, 09:24 AM
If someone hadn't told you SL uses a 32bit kernel by default, you'd never have known. Having a 32bit kernel doesn't affect your ability to use 64bit software, it just means you aren't restricted to only KEXTs that have been compiled for 64bit.

As for the person who said "it feels snappier in 64bit mode". Look up this word: placebo.

Well on a 64 bit kernel in 64 bit mode on dual quad nehalem processors, I get an average of 10-15 % improvement in all processor, floating point and memory MacBench tests. Disk access however is on average slower in 64 bit mode.

This was contrary to the processor slowdown i was expecting.

BeePee
29th August 2009, 09:46 AM
Imac8,1
Terminal says EFI64
Boot 6+4
Sys Software says NO

ChrisR_12
29th August 2009, 10:03 AM
Imac8,1
Terminal says EFI64
Boot 6+4
Sys Software says NO

Yea i get the same thing.

BeePee
29th August 2009, 11:48 AM
Imac8,1
Terminal says EFI64
Boot 6+4 keys
Sys Software says NO
Tried Keljian post using Startup Mode Selector
Bingo!
Sys Software says 64 bit YES

fotografer
29th August 2009, 09:23 PM
I have only tried the "6+4 keys on bootup" once and promptly rebooted back to 32-bit kernel as my Boot Camp partition did not show up.

Possibly linked to the fact that I have MacFuse and NTFS-3G installed which are still 32-bit extensions?

Anyway, likely will try again.

In any case, Snow Leopard has been a real easy install and a lot of things just integrate and/or perform more smoothly.

Edit/update : Seems that NTFS-3G was the culprit. Disabled it, rebooted in 64-bit kernel mode, and the Bootcamp partition appears. Now contemplating if the loss of write-capability to NTFS volumes is lesser than the perceived 64-bit wholesome goodness gained.

matthew858
29th August 2009, 09:38 PM
Using this tool (http://www.ahatfullofsky.comuv.com/English/Programs/SMS/SMS.html), it seems to think that I have the right equipment for 64 bit:

http://web5.twitpic.com/img/26355166-36cc7a7b54f62aa9f2bbf1582eff9963.4a991306-scaled.png

But I have an iMac7,1 which Apple doesn't officially support. I hope Apple lets us boot into 64 bit!

nibbles
30th August 2009, 08:04 AM
My macbook still running leopard returns "firmware-abi" = <"EFI64">

markh
30th August 2009, 10:52 AM
Won't boot into a 64btt Kernel on a MacBook 4,1 even with 64bit cpu and 64bit EFI

Exocet
30th August 2009, 10:52 AM
Source: Snow Leopard Currently Restricts 64-Bit Booting To Newer Macs | Gizmodo Australia (http://www.gizmodo.com.au/2009/08/snow-leopard-currently-restricts-64-bit-booting-to-newer-macs/)

Update: We’ve gotten some explanation from Apple on the issue at hand. The deal is, Mac desktops and laptops will indeed boot with a 32-bit kernel, while only the Xserve will be 64-bit. But this won’t matter to the consumer. Our Apple contact explained:


The 32-bit kernel fully supports 64-bit applications, all system libraries that 64-bit applications use are fully 64-bit, and 64-bit applications have a full 64-bit virtual address space of 16 exabytes available to them on Mac OS X. The primary benefit of a 64-bit kernel is to improve the efficiency of accessing over 32GB of RAM.

As a whole, machines with lots of RAM (over 4GB) are more efficient with a 64-bit kernel, but even though consumer Macs will have a 32-bit kernel, all Intel-based Macs will run 64-bit programs automatically, which gives you the most obvious benefits. So really the only benefit to having a 64-bit kernel is if you’ve got 32GB of memory, a frankly monstrous amount of RAM, and hell, the hardware won’t even allow that much. All 64-bit applications will run on the Macs with either Intel Xeon or Intel Core 2 Duo processors, so this 32-bit brouhaha is pretty much a misunderstanding.