Home Forums Mac Software Mac Operating Systems Snow Leopard requirements...

I understand Snow Leopard will have some features/speed improvements that will require certain video cards that are only in more recent Macs. Is this the case? I have a 24" iMac purchased 07/2008. How do I find out if my iMac meets the requirements, and if not, how will this effect performance on my machine?

Checking the advertised system requirements... Your iMac won't have Quicktime HD video acceleration, but that's not necessary for a great experience. It also won't support OpenCL, which is probably to what you're referring. OpenCL is supposed to allow your GPU to process things beyond graphics, thereby increasing processing power, but it's not entirely clear what apps will actually support that, how efficient it will be, nor what actual yield to expect from it. In any case, your 10.6 experience won't be the worse for wear, it just means you won't be able to take advantage of some of the potential bonus, if ever and whenever it materializes in real-world computing. But then again, you didn't pay for a more expensive machine with a higher-end card, so you're not out anything.

Thanks for the help. I also came upon this article at osnews.

http://www.osnews.com/story/22009/Snow_Leopard_Seeds_Use_32bit_Kernel_Drivers_by_Default

My iMac has the EFI 64 firmware. The Snow Leopard seeds apparently boot into the 32bit kernel by default. Only the Xserves boot 64 bit by default. This makes sense to me because of the driver issues mentioned. It will take time to go full 64 bit I'm assuming.

Oh, I plan to move to Snow Leopard quickly now since Rosetta will be available as an optional install. Thanks again.

Full 64 bit will only be of marginal value until the applications have been rewritten to take advantage of it. Even then many applications are unlikely to ever be converted because they would gain little from the conversion other than bragging rights. So expect it to take a long time before you will be seeing any noticeable, much less major, benefit from going 64 bit.

would gain little from the conversion other than bragging rights

that and the ability to address more memory I believe?

A Terabyte of RAM?????


::: drool! :::

True, but how many applications can effectively use more virtual memory address space? Photoshop if you are creating bill board size images, pro level video editing apps maybe, and perhaps some games and you have about exhausted the list. Servers and server apps on the other hand are much more likely to be able to use the additional address space.

Let's not get too worked up about this. Leopard (10.5.x) runs both 32 and 64 bit applications already. Snow Leopard (10.6.x) brings two more things to the 64-bit transition table: (1) all included applications, such as iPhoto, will be dual 32/64-bit and (2) the kernel itself will be dual 32/64-bit.

From an application's perspective, if it is already 64-bit, the transition makes no practical difference.

Running the kernel in 64-bit brings a couple of potential advantages, and one clear disadvantage. As to the advantages, it will support hardware with almost unimaginable amounts of RAM (not currently shipping, and mind-bogglingly expensive if one had to fill those slots) along with potential speed ups in certain operations due to the micro-architectural changes in the 64-bit instruction set (mostly more registers). On the down-side, all those 32-bit drivers you have for USB (and other) hardware will not function in a 64-bit kernel.

As with the Windows transition to 64-bit, you'll need all new drivers. By running the kernel in 32-bit mode by default, Apple avoids that downside and preserves the investment you've made in your existing hardware. Unlike Windows, you can still run all of your 64-bit apps under a 32-bit kernel.