It seems that ATi is preparing two differnet chipsets for the AMD64 platform, the RS480 with integrated DirectX 9 graphical solution, a RX480 without integrated graphics and the IPX400:
ATI RS480 will, as expected yesterday, boast with PCI Express interconnections support, as well as incorporate a DirectX 9.0 graphics core. It is projected to be sampled in the first quarter of 2004 and will go into mass production sometime in the second or the third quarters next year. The chipset will have Unified Memory Architecture for its graphics core, therefore, do not expect its integrated DX9 RADEON logic to offer you stunning speed in demanding DirectX 9.0 applications. ATI RX480 is the same as RS480, but without any integrated graphics – probably a simple PCI Express 16x (PEG x16) tunnel.
ATI IXP400 is said to provide 4 Serial ATA-150 ports, Parallel ATA-100/133 support, 8 USB 2.0 ports, AC’97 audio and so on. The South Bridge is scheduled for sampling in the Q1 2004 and for mass-production in Q2/Q3 2004.