The successor to ATI's current southbridge, the SB450, has launched alongside the Canadians' updated RD580 platform for AM2.
The SB600 corrects some of the problems found in SB450, including USB performance. It integrates Intel's Azalia high definition audio as well as a native SATA 2 controller, supporting RAID 0, 1, 10 and 5.
Interestingly, there doesn't appear to be any networking built into the chip, with ATI apparently choosing to leave network configurations for individual board partners to sort out by integrating third party chips from companies like Marvell or Broadcom.
ATI's new southbridge will be integrated on many new boards containing the updated AM2 version of the Xpress 3200 chipset, aka RD580. Many ATI mainboard partners use a ULi southbridge on current boards, but with NVIDIA now owning ULi, that situation may be difficult to continue.
We will be bringing you a performance comparison of nForce 5 versus the new RD580 very soon, so stay tuned! In the mean time, let us know your thoughts over in the forums.