The US Apple Store is offering Radeon add-on kits for its Power Mac G4 and Power Mac G4 Cube models.

This will enable those using Macs equipped with slower RAGE 128 Pro graphics card to upgrade. The new cards feature ATI's Radeon graphics chip, its flagship graphics processor.

The $249 add-on kit's architecture differs from previous chip designs by offering features that ATI says will speed up the display and quality of 3D graphics.

Apple is also offering the Radeon card as an option for build-to-order systems purchased through the Apple Store.

The Radeon Kits for Power Mac G4 and the Cube have an ADC connector to make them compatible with Apple's newer 17-inch Studio Display, as well as its newer 15-inch and 22-inch flat-panel displays.