I've been receiving a few emails of people concerned about the performance of the Mac mini under Mac OS X 10.4 (Tiger) - especially with regards to support for Tiger's Core Image technology. Core Image is basically a cool label for GPU rendered UI, whereas OS X 10.3 today is CPU rendered but GPU composited (if you have an appropriate GPU). The problem with the Mac mini is that the Radeon 9200 it has in it is based on the RV280 core, which is not a fully floating point GPU. The question then becomes, will Core Image require Shader Model 2.0 or will the 9200's Shader Model 1.4 suffice?

I tend to believe that Apple will have essentially the equivalent of multiple rendering paths for Core Image, with some features made available to Shader Model 2.0 GPUs that aren't made available to SM 1.x GPUs and the default case being revert to a fixed function, non-Core Image enabled UI. But that's just an assumption, what I really want to know is if anyone has tried the latest Tiger builds on the mini and if so, is Core Image support enabled and is it fast?

The other problem with the mini's Radeon 9200 is it's only got 32MB of memory attached to its 64-bit DDR memory bus. I'd expect Core Image to be more GPU memory intensive than Panther's rendering and compositing engine, which means that memory size and bandwidth are important. The memory bandwidth aspect of things should be ok, but it's the memory size that I'm worried about. If you've read my review you'll remember that I mentioned at resolutions greater than 1280 x 960 Exposé started to get choppy. If the 9200 is in some way supported by Core Image, I'd hope that the minimum resolution at which you can still have smooth Exposé and Dashboard functionality remains as high as it is currently under Panther.

The reason this is something that concerns me now is simply because given the popularity of the mini, I want to make sure that recommending it won't leave users with a less than satisfactory experience in a handful of months when the next version of Mac OS X is released. Any first hand feedback? Post it here or drop me an email.
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  • Scott - Saturday, February 26, 2005 - link

    Hi,

    I'm using a Mac Mini with Apple 23" running @ 1900 x 1200. Expose runs fine with 14 windows open. I see no choppiness whatsoever; no different to my 17" PB.

    Hope this helps.

    Scott
  • oingo - Tuesday, February 22, 2005 - link

    >Um....so is pretty much every 3D game.

    Yes, but 3D game engines aren't made available to any application which wants to use them as part of the core OS API are they?
  • msva124 - Friday, January 28, 2005 - link

    >Core Image is actually a floating-point image processing library.

    Um....so is pretty much every 3D game.
  • bob661 - Friday, January 28, 2005 - link

    Is that added overhead for the CPU?
  • Ecgtheow - Thursday, January 27, 2005 - link

    You're a little off there, Anand (although you're not alone). Core Image is actually a floating-point image processing library. If the GPU is advanced enough, the calculations can be done on it. If not, it is done on the CPU. Apple's web site has about the only real info that isn't under NDA:

    http://www.apple.com/macosx/tiger/coreimage.html

    Here's a relevant bit: "For computers without a programmable GPU, Core Image dynamically optimizes for the CPU, automatically tuning for Velocity Engine and multiple processors as appropriate."
  • ProviaFan - Thursday, January 27, 2005 - link

    1GB isn't going to make any difference in the rendering performance, because the textures that won't fit in the 32MB of video ram still have to be transferred across the AGP bus, which is much slower than grabbing them "locally" out of video RAM that's on the "card."
  • RMSistight - Thursday, January 27, 2005 - link

    I'm also worried about my monitor because I'm currently running at 1280 x 1024. If what Anand says is true about Expose, then it's going to be a HUGE turn off. Hey Anand, will Expose be choppy if I had 1GB of memory? Just curious.
  • RMSistight - Thursday, January 27, 2005 - link

    I too am curious about the performance of Mac OS X Tiger on the Mac Mini. After watching the Keynote at MacExpo, I specifically wanted to purchase the Mac Mini along with it's Tiger OS. GTaudiophile also makes a good point about the video card. ATI could have easily dropped in an 9600 Pro with more memory. I think this issue here should be left up to the Apple engineers to decide.
  • GTaudiophile - Thursday, January 27, 2005 - link

    Makes you wonder why Apple/ATI couldn't agree on at least a Radeon 9600 (X600) based GPU with 64-128MB of memory. You know ATI has the supply. Was it a cost issue? ATI wouldn't go down far enough on the price? Was it a heat issue? Power issue?
  • Holger Eilhard - Thursday, January 27, 2005 - link

    Very good post. I'm also interested in this...

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