Originally on http://www.apple.com/macosx/jaguar/quartzextreme.html * Requirements:
Quartz Extreme functionality is supported by the following video GPUs: NVIDIA GeForce2 MX, GeForce3, GeForce4 MX, or GeForce4 Ti or any AGP-based ATI RADEON GPU. A minimum of 16MB VRAM is required.
Scroll down the page for QE, and you'll see this on the bottom right next to the performance comparison graphs. My understanding is that Quartz is really improved on all systems, especially G4's, but Quartz Extreme is only enabled for the (mentioned in above quote) supported graphics cards, and offers what is supposed to be a huge performance improvement. You will see an improvement without a GeForce card or Radeon AGP, just not as much as you would if you had such a card.
