Latest Snow Leopard build limits most Macs to 32-bit mode

http://arstechnica.com/apple/news/2...ard-build-limits-most-macs-to-32-bit-mode.ars

Latest Snow Leopard build limits most Macs to 32-bit mode

Apple has said that Mac OS X 10.6 Snow Leopard will run in full 64-bit mode on any 64-bit capable Intel processor. In fact, Snow Leopard's 64-bitness is one of its highly touted under-the-hood features. But so far, the purported golden master build still won't boot in 64-bit mode on a number of 64-bit capable models.

That build, 10a432, included release notes that detail running Snow Leopard in 64-bit mode, meaning the underlying kernel is taking full advantage of the 64-bit capabilities of the hardware. According to the document, Apple is still asking developers to develop and test 64-bit versions of any kernel extensions—most commonly device drivers—as Apple has been asking developers to do for some time. Snow Leopard running in 64-bit mode can only load drivers that are 64-bit, and though Apple provides many common hardware drivers, some devices simply won't work without a custom one.

Only Intel Xserves will boot 64-bit by default, and Apple lists a number of models that are capable of booting in 64-bit by holding down the '6' and '4' keys while starting up. Even still, not all machines with 64-bit processors will boot into 64-bit mode. Specifically, some earlier Core 2 Duo-based Macs have a 32-bit EFI firmware, and despite the fact that a 32-bit EFI can load a 64-bit kernel, Apple (so far) limits these machines from doing so. Ironically, a tool to enable hackintoshes to boot Mac OS X can enable Macs with 32-bit EFI firmware to boot Snow Leopard in 64-bit mode. Luckily, even if Snow Leopard boots into 32-bit mode, it can still load and run 64-bit applications just fine. And, oddly, Apple notes that Snow Leopard Server builds boot into 64-bit mode by default—why the client version still has the limitation isn't clear.

These details suggests to us in Orbiting HQ a couple of things, though. Apple says that Snow Leopard is part of its transition to 64-bit. While Snow Leopard is a huge step in that direction—all the included applications in Snow Leopard are 64-bit, for instance—not all of Apple's machines in the last few years are 64-bit capable (like the MacBook1,1 I'm typing on right now). Also, as of build 10a432, it's possible that even Apple might not have all the necessary device drivers for all 64-bit-capable Macs fully tested and ready. Still, since Apple lists a 64-bit Intel processor as the only requirement for 64-bit mode, we're sure Apple will have this sorted out before Snow Leopard officially launches.

Of course, whether booting every 64-bit capable machine into 64-bit mode by default is the right thing for users is still not certain. There are a number of performances gains to be had from doing so, but if it comes with compatibility headaches, Apple may be better off letting those will older machines decide for themselves to force 64-bit mode if they desire. Less savvy users will be none the wiser, as it will boot in 32-bit mode and run 64-bit applications without issue.

 

your title is misleading... apple does not limit it to 32 bit mode... they DEFAULT to 32 bit mode. which is different. You can edit a .plist file to make it always boot 64 bit kernel without having to hold 6 and 4 every time if you really want.

While this seems like a bad thing, its actually better for the customer at the moment with all the issues with 3rd parties making things right for 64 bit mode... Apple is just playing it safe... but they can easily change this in the future with 10.6 without making anyone buy aything new.

The cool thing is though.. even running a 32 bit kernel in Snow Leopard, you can still run 64 bit apps.

 

Sorry not my title, the story title, I am not saying what it says is correct it`s just a topic for discussion.

 

Yes, this was debunked very quickly. Here's an article that explains a bit better.

 

Some of the models are limited to 32-bit mode. Apple doesn't provide 64-bit drivers for every model and for some models older EFI versions limits them to 32-bit only.

 

some, not most

 

Yeah, I read an article yesterday that pretty much said the same thing in that booting into 64bit is really only advantageous on systems with greater than 32GB Ram. So this whole thing is a non-issue.

 

or for developers who actually need a large numbers that can only be shown as unsigned long integer numbers with size 2^64 (unsigned) or 2^64 -1 (signed)

 

Wow.. This is why Rosetta is included on the Install DVD bundled applications people..

 

what does that have to do with anything? The discussion is over 32 and 64 bit... x86 and x86_64... nothing to do with PowerPC applications.

 

By Default v10.6 boots via 64 Bit. While using the OS, if anything happens in which it is needed for 32 Bit only, a window will appear asking that Rosetta is needed. I have been using v10.6 for about a week now. And that is pretty much how it works, its that simple.

 

I think some of you are confused with booting into 32bit vs. using 64bit applications. the advantage of booting into 64bit kernal is to better utilize if you have more than 32GB of RAM. you can boot into 32bit kernal and still use 64bit applications. your imac and laptops don't support 32GB of RAM to begin with so thats a moot point. booting into 64bit kernal doesn't make your computer run faster, its for better RAM management.

 

cant really follow what your saying...

Rosetta is software used to run 32 bit PPC code on Intel Macs... have they changed Rosetta to be something different? Maybe your running older PPC code and thinking its just a 32 bit thing?

Native x86 code, 32 or 64 bit runs on Snow Leopard without the use of Rosetta.

 

hey if sl runs in 64 bit, does that mean parallels will run faster and my virtual windows will lag less?

 

nope.... maybe it will if Parallels makes a 64 bit version... but i gave up on Parallels after version 4 came out. VMware already runs quicker for me.