09-03-2009, 08:52 AM

Is it true that if your Mac has a 32-bit EFI you will not get the full speed enhancement from Snow Leopard that someone with a 64-bit EFI would?

09-03-2009, 09:34 AM

Originally Posted by toMACsh

Is it true that if your Mac has a 32-bit EFI you will not get the full speed enhancement from Snow Leopard that someone with a 64-bit EFI would?

Read the Sticky thread:

64-bit and Snow Leopard – What 64-bit means for you

09-03-2009, 01:13 PM

Originally Posted by D3v1L80Y

Read the Sticky thread:

64-bit and Snow Leopard – What 64-bit means for you

My question was not addressed in that post.

09-03-2009, 01:24 PM

Originally Posted by toMACsh

My question was not addressed in that post.

Yes, it was.
Your question was:

Originally Posted by toMACsh

Is it true that if your Mac has a 32-bit EFI you will not get the full speed enhancement from Snow Leopard that someone with a 64-bit EFI would?

From the Sticky Thread:

Originally Posted by Sticky Thread

Q: If I don’t have a 64-bit capable processor, can I still use Snow Leopard?
A: Yes but you won’t get any of the arguable benefits that come with 64-bit computing. This does not render Snow Leopard useless as many of the great enhancements and improvements are independent of the increased 64-bit support such as Grand Central Dispatch and OpenCL. For descriptions of these technologies, go here. In fact, for the near future at least, those who boot into a 64-bit kernel will likely experience more problems than those who stick with the default 32-bit kernel.

09-03-2009, 04:05 PM

The EFI only limits what kernel you can boot into. You can use 64-bit applications with a 32-bit kernel as long as your processor is 64-bit capable.

09-03-2009, 05:45 PM

If it boots into 32bit kernel, doesn't it limit the amount of memory which can be used by the OS?

09-03-2009, 08:51 PM

Originally Posted by D3v1L80Y

Yes, it was.
From the Sticky Thread: ...

Sorry, I don't think that does answer my question specifically.

Originally Posted by vansmith

The EFI only limits what kernel you can boot into. You can use 64-bit applications with a 32-bit kernel as long as your processor is 64-bit capable.

This gets closer. I have a Core 2 Duo processor, which is 64-bit. But (bit but?) I only have a 32-bit EFI. Isn't this and that from your reply really two different ways of describing the same thing? I realize that I don't know what I'm saying when I call my processor 64-bit.

I'm probably just getting lost in the terminology.

Wiki-p says EFI (Extensible Firmware Interface) is "a specification that defines a software interface between an operating system and platform firmware." And, "the kernel is the central component of most computer operating systems. Its responsibilities include managing the communication between hardware and software components."

So EFI is the kernal? (I've just made sergeant.)

09-03-2009, 09:13 PM

No, it's not.

09-03-2009, 09:38 PM

Originally Posted by toMACsh

This gets closer. I have a Core 2 Duo processor, which is 64-bit. But (bit but?) I only have a 32-bit EFI. Isn't this and that from your reply really two different ways of describing the same thing? I realize that I don't know what I'm saying when I call my processor 64-bit.

I'm probably just getting lost in the terminology.

Wiki-p says EFI (Extensible Firmware Interface) is "a specification that defines a software interface between an operating system and platform firmware." And, "the kernel is the central component of most computer operating systems. Its responsibilities include managing the communication between hardware and software components."

So EFI is the kernal? (I've just made sergeant.)

The EFI is one level lower than the operating system as illustrated by this picture. The kernel is part of the operating system. Like your definition states, it is the central part of the OS, responsible for quite a bit of low level stuff.

If you are this confused by the terminology and the differences, perhaps it would be best to leave it alone. You don't need to know the difference to effectively operate your machine.

09-04-2009, 08:44 AM

Originally Posted by vansmith

The EFI is one level lower than the operating system ... The kernel is part of the operating system.

Thanks. That diagram is helpful. The problem with the terminology is that others use it incorrectly, which is the source of my confusion.

Now, back to my original question, which still has not been addressed directly. It's a simple question, really; a yes or no question:

If one has a 64-bit kernel, but a 32-bit EFI, then is it true that configuration cannot take full advantage of the enhanced speed of Snow Leopard?

While I don't need to know in order to use my Mac, I want to know more just for the sake of increasing my knowledge base.

I'm assuming that newer Macs have a 64-bit EFI.

09-04-2009, 11:41 AM

Originally Posted by bobtomay

No, it's not.

Are you trying to be funny???

I'm seeing a lot of:

"Yes it is...No it's not...Yes it is...No it's not!"...in this thread.

Sounds like Pee-Wee Herman:

I know you are...what am I! Ha Ha!

..........

- Nick

09-04-2009, 12:49 PM

Originally Posted by toMACsh

If one has a 64-bit kernel, but a 32-bit EFI, then is it true that configuration cannot take full advantage of the enhanced speed of Snow Leopard?

On Macs, you can't boot into a 64-bit kernel with a 32-bit EFI (right now) so the question doesn't really make sense. To quote this article, "Only Macintosh machines with a 64bit EFI are able to boot the 64bit Snow Leopard kernel and kexts; this is an artificially implemented limitation by Apple, as 32bit EFI can boot a 64bit kernel just fine." As you can see, you can't boot a 64-bit kernel with a 32-bit EFI right now on Macs. If you could, you would get the benefits of having a 64-bit kernel just like everyone else.

On top of this, quite a bit of the refinements are independent of the 64-bit improvements including Grand Central Dispatch and OpenCL. There is much more to the optimization of OS X than just increased 64-bit pervasiveness.

09-04-2009, 01:12 PM

On most computer forums, there's no such thing as a stupid question. It seems to me that you've answered my question with a "yes". I appreciate the more complete explanation.

So, if this is an artificial limitation, it seems conceivable that Apple could decide to remove it. But, if it's a hardware issue, current Macs with the 32-bit EFI would still be out of luck, no?

09-04-2009, 01:28 PM

Originally Posted by toMACsh

So, if this is an artificial limitation, it seems conceivable that Apple could decide to remove it. But, if it's a hardware issue, current Macs with the 32-bit EFI would still be out of luck, no?

Yes, it is conceivable that Apple could remove this limitation. That said, you don't want to run a 64-bit kernel now anyway because of the lack of 64-bit driver support (a 64-bit kernel can only load 64-bit kexts).

It's not a hardware issue (in terms of EFI) as illustrated by the article I previously posted - the "limitation" that only allows a 32-bit kernel to be loaded by a 32-bit EFI is artificial. The only hardware limitation that affects the loading and use of a 64-bit kernel and applications is your processor. If you're machine has a 64-bit capable processor, you can run a 64-bit kernel and applications. So, if you have a 32-bit EFI, you can load a 64-bit kernel (assuming the EFI limitation is removed by Apple) as long as you have a 64-bit capable processor.