Motherboards based on a particular chipset usually share a feature base. A chipset, however, usually consists of two components: The Northbridge, which includes the processor and graphics interfaces; and the Southbridge, which takes care of I/O and basic controllers. Southbridge components include mass storage controllers, USB controllers, Ethernet controller, audio capabilities and so forth. ATI has been taking heavy criticism for its current Southbridge component SB450, because it does not always live up to expectations. USB performance is not good enough, and the feature set is said to be somewhat average, with RAID missing, and no support for Gigabit Ethernet. While advanced features here are not an issue for the vast majority of customers, they are a requirement both to sell in the enthusiast space and to build up a reputation.

Thanks to ATI using PCI Express to link its Northbridge and the Southbridge, ULi Southbridge components were deployed on several Radeon Xpress 200 motherboard products. In fact, we already spent some time to find the best platform solution for Athlon 64 machines. Thanks to the ULi M1575, Radeon Xpress 200 motherboards were not too far away from Nvidia's complete nForce4 solutions (although these do have their own little troubles).

The Crossfire Xpress 3200 is a completely reworked and shrunk Northbridge. There are 32 PCI Express lanes rather than 16, enabling much more bandwidth for connector-free dual graphics setups.