core image
Okay lets see if we can get this straight about core image
Core image, as the name implies, is built into the kernel of the OS. Apple includes a number of core image filters (image units) that are easily accessible via API's for developers to use in their apps. According to Apple, most developers will never need to venture much further than API calls to these built-in filters, but, thanks to core image's extensibility, they can develop their own custom filters should the need arise. I'm sure Apple would be thrilled if Adobe develops the next version of Photoshop to use core image filters, because performance-wise it would blow away Photoshop on other platform. More on that in a second...
It's important to understand the difference between quartz extreme and core image. Quartz extreme, which makes heavy use of open GL, required a compatible graphics card. It wasn't merely an option to "boost" quartz extreme performance, if you didn't have a compatible card, you didn't get quartz extreme. Period. There wasn't a software fallback in any layer of the OS to enable quartz extreme without the required graphics card hardware. That's fundamentally different than core image, which dynamically optimizes itself for whatever hardware is present on your machine. Sure, you'll see the best performance in some cases (but not all if core image determines the CPU can better optimize performance) with a pixel programmable card, but every tiger compatible machine (including the poor mac mini) will see a benefit, just as every Panther compatible machine saw a benefit from apps that utilized core audio and audio units - because of its integration into the kernel of the OS.
Back to the Photoshop example. If Adobe releases a core image enhanced version of Photoshop on May 10th, every Tiger compatible machine would see a performance increase from the older Panther version of Photoshop, including the poor mac mini. Because core image in Tiger optimizes how applications can process image filters in a way that wasn't possible on Panther, or any other OS for that matter. Of course, a G5 with a pixel programmable graphics card will scream, but that doesn't mean that the poor mac mini is left out. On the contrary, it will see a performance boost as well, commensurate with its hardware set. Core image technology is like a rising tide that will lift all Tiger compatible machines.