South bridge chips
SiS's south bridge roadmap contains a small assortment of chips compatible with both its Intel and AMD-oriented north bridge chips. These south bridge chips aren't divided into value, mainstream, or performance markets, but it's pretty easy to segment them based on features.

Two of SiS's new south bridge chips will enter mass production this month. The first of these is the 965L, which features eight USB 2.0 ports; two ATA/133 controllers; two Serial ATA ports with RAID 0, 1, and JBOD support; two PCI Express x1 interfaces; a 10/100 Fast Ethernet MAC; and AC'97 audio.

To complement the 965L, SiS is also rolling out a 965 south bridge that adds a Gigabit Ethernet MAC and two more Serial ATA ports. With support for a total of four Serial ATA drives, the 965 will also be capable of RAID 0+1. Both the 965 and 965L use a 1GB/sec MuTIOL north/south bridge interconnect.

Later this year, SiS will add the 966 south bridge to its lineup. The 966 will support 10 USB 2.0 ports, two channels of ATA/133, four Serial ATA ports with AHCI and RAID,, Gigabit Ethernet, High Definition Audio, and four PCI-E x1 interfaces. To ensure that all those integrated peripherals have enough north/south bridge bandwidth, the 966 will sport a new MuTIOL interconnect that offers 2GB/sec of bandwidth. The new interconnect doubles the bandwidth of SiS's current MuTIOL link, and it will only work with upcoming 761, 656, 656FX, and 662 north bridge chips.

Conclusions
SiS's desktop chipset roadmap looks promising overall. All the must-have features are there, including four-port Serial ATA RAID, Gigabit Ethernet, PCI Express, and High Definition Audio. However, feature support doesn't guarantee feature performance. We'll have to wait for these new chipsets to hit the market to determine how competitive they really are with the latest from Intel, NVIDIA, VIA, and ATI.

And getting to market, at least the enthusiast market, may be SiS's biggest challenge. Although the performance of SiS's chipsets is often as good as—if not better than—the competition, motherboard manufacturers have traditionally been reluctant to use SiS chipsets in enthusiast-oriented motherboards. If SiS is able to execute its forward-looking roadmap and offer competitive performance along the way, perhaps that could change.