64-bit Snow Leopard defaults to 32-bit kernel
Summary: Apple's OS X 10.6 operating system Snow Leopard by default loads with a 32-bit kernel, despite running 64-bit applications.
While it ships with a number of 64-bit native applications, Apple's kernel itself defaults to 32-bit, unless the user holds down the "6" and "4" keys during boot time, at which point the 64-bit kernel is loaded. Only Apple's X-Serve products, using Snow Leopard Server, boot into a 64-bit kernel by default.
See also: Snow Leopard: Special Report
"For the most part, everything that they experience on the Mac, from the 64-bit point of view, the applications, the operating system, is all going to be 64-bit," Stuart Harris, software product marketing manager at Apple Australia said.
Harris said that at this stage there were very few things, such as device drivers, that required 64-bit mode at the kernel level but the option was available.
"But we're trying to make it as smooth as possible, so people don't end up finding that 'oh, that doesn't work' because it's not available yet," he said.
An older mid-2007 MacBook with a 32-bit EFI chip, forced to a 32-bit kernel can't register the full 4GB RAM. (Credit: CBS Interactive)
There appears to be no way within the GUI to make this change permanent, requiring the editing of the com.apple.Boot.plist file to make the change — a text-based configuration file. Users have already released applications to address this issue.
Older Macs with a 32-bit EFI chipset are prevented from loading the 64-bit kernel, although there are claims that this is an arbitrary decision by Apple rather than a technical concern, with a hack using the Chameleon boot loader devised to get around the lock out.
This raises another problem — if equipped with 4GB RAM, those with a 32-bit EFI chip are not capable of making use of the full amount, our mid-2007 MacBook only showed 3GB available for system use through Activity Monitor despite having 4GB installed, not delivering the true 64-bit experience. Newer machines equipped with a 64-bit EFI chip running a 32-bit kernel seemed capable, with Activity Monitor reporting 3.75GB RAM available, as 256MB was put aside for the GeForce 9400M graphics chip.
It is unknown at this stage what sort of performance implications running 64-bit applications on a 32-bit kernel will have compared to a 64-bit kernel.
While a large portion of the OS has been optimized and updated, some applications, such as DVD player, Front Row, Grapher and iTunes are still 32-bit only, and some extensions are still run as a Universal Binary, despite the PPC architecture no longer being supported.
Some processes are still running as Universal Binaries. (Credit: CBS Interactive)
Apple also released Snow Leopard Server today, but were unable to detail the reasoning behind dropping ZFS support for the operating system, a much touted feature during the development stage.
This article was originally posted on ZDNet Australia.
Kick off your day with ZDNet's daily email newsletter. It's the freshest tech news and opinion, served hot. Get it.
Talkback
seriously
If it is the Intel 960 chipset it was only supported for 2GB RAM. I have one its a chipset limitation every PC or MAC that has that chipset suffers from.
Great operating system upgrade. Only petty about...
All major OSX applications are now fully 64 bit. Except some of them are not <i>quite</i> there yet. Will you have to pay for the next upgrade to 64bits as well?
Grand Central Dispatch will greatly improve performance. <b>Except not for any current applications and not much for current hardware.</b> You will have to buy a new Mac to take full advantage of GCD. Then you can hope that applications have been rewritten to take advantage of GCD. Which are <i>major</i> rewrites (it is a paradigm change; not just a simple replacement API).
OpenCL can tap into the computing power of the graphics chips. <b>Except many current macs do not support it or use an underpowered "onboard" chip</b>. But you can buy a new Mac with a more powerfull chip. Then you can take advantage of it. Or rather, you can hope that applications are being rewritten to take advantage of it, because that is *also* a major undertaking.
But you can now connect directly to Exchange server from a number of refreshed apps. <b>Except it requires that the server runs Exchange 2007 with the <i>latest</i> service pack deployed</b>. Few organizations are there yet. But hey, at least you will not have to throw additional $$ at Apple to take advantage of this one.
A new malware protection to protect the "secure by design" operating system against the nonexistent threats. <b>Except it only protects against 2 trojans</b>, it updates infrequently and it only protects against malware piggybacking files received through a few select channels.
Look at the bright side. You <b>do</b> get Expose' integrated with the dock.
I can see why Apple has tried to downplay the expectations to this one.
Em<b>phas</b>is
chips, which after three years isn't unexpected. It has streamlined a lot of
code, which is long over due.
also most of the criticisms listed are the feature set that is going to leave
behind older hardware as the hardware didn't support them. The
comment about 'most macs use an underpowered 'onboard' chip refers to
the only Mac using the Intel graphics chipset, a Mac Book.
Sounds like NonZealot to me.
I don't know if you realize this
"The views expressed here are mine and do not reflect the official opinion of my employer or the organization through which the Internet was accessed."
Underpowered GPU
crippled with the Intel GMA chips. This is about the only thing that
sucks on my Mini. I can see I'm probably not going to get a huge
performance boost from 10.6 on my older mac 8(
Getting a little disk space back will be nice, NZ$60 for 8GB is
probably about Apples going dollar to GB ratio based on what they
charge for disk upgrades 8)
A pitty it doesn't come with iLife09 unless you get the macbox, but I
already have iWork09, so not worth the money for me. As long as
EyeTV still works I'll consider it a successful upgrade.
I'm still saving up for a new Mini for christmas though. There is
nothing else with its small footprint ans silent running that is still a
full powered PC.
Hmmm
For months we've heard nothing regarding 64-bit except
Except, of course, when OS X doesn't boot a 64-bit kernel.
Then, all of a sudden, not having 64-bit puts you in the
depths of the dark ages.
Ummmmm.....
Course Mac's are made for mouth breathers, so this probably isn't a big deal.
Then don't do it...
I know for a fact that OS X could address as much RAM as you could load into a G5 in 2002.
This is not the first "64-bit" OS X, but it's an evolutionary step in the right direction. I haven't used many 64-bit Windows OSes, but I imagine they were similarly not fully 64-bit (i.e. not every system process that ran on your computer was a 64-bit process, drivers were not 64-bit or compatibility was an issue).
well
Win XP 64 bit vs 2003 (based on Windows Server 2003 code) came out in March 2003.
Win XP Professional x64 supporting x86-64 extensions implemented in early AMD and INtel x64 processors released in April 2005. This is the most popular one as it supported all major consumer chips.
So we have 8 or 9 years for the first one, >6 years for the second, and >4 years for the third and main one. Considering that even 2 years in this industry is 'ancient history', the fact that SL is not completely native x64, does in fact, put it right back in the dark ages. I mean common, 4 years MINIMUM for Windows - all without removing support for 32 bit applications! (16 bit has gone the way of the dodo, however)
And also, I've been saying for YEARS (4 of them) now that 64 bit is everything BUT overrated and I've heard nothing different on forums except from those that weren't using it themselves.
"The views expressed here are mine and do not reflect the official opinion of my employer or the organization through which the Internet was accessed."
Okay...
I believe OS X hasn't been 'branded' a 64-bit OS for several reasons. One is, as you say, it hasn't been completely 64-bit. Another is that the 64-bit support that has been integrated over time is transparent. It's not marketed as 'OS X64' and there's no need to determine whether an application or driver is 32-bit or 64-bit, they just work.
OS X has definitely taken a different road to where it is today than Windows has, but I wouldn't say that it's any worse, just different.
Hm wierd
Extremely stable?
RE: Extremely stable?
Oh I am sure there is a reason
Precisely
The other most common cause of BSOD is hardware issues - a 6 year old machine of mine that was running XP, then Vista and more recently, Win7, started BSODing. Turned out one of the memory cards was dying. Replaced the card and has been running 24x7 without a problem ever since.
Excatly
"The views expressed here are mine and do not reflect the official opinion of my employer or the organization through which the Internet was accessed."
Funny that
party; driver, plug-in, hardware etc.
On the much rarer occasions when someone reports a less than stellar
experience with Mac OS or Linux then they are in like Flynn, pointing the
finger viciously at the "enemy".
Sigh. You people have NO idea just how tedious, biased, predictable, and
unnecessary you are.
I can guarantee you
"The views expressed here are mine and do not reflect the official opinion of my employer or the organization through which the Internet was accessed."
You're overlooking one thing...