The most striking feature of the SiS630S chipset is its high level of integration. No other current PC chipset combines not only the northbridge and video, but a full-featured southbridge as well into a single chip. SiS is well ahead of VIA, ALi and Intel in this matter. VIA has just recently come up with an integrated northbridge with video, to our knowledge, ALi has their integrated TNT2 chipset, and Intel's Timna has been canceled, so for now, SiS's chipset is far more integrated than the competition.

Integration does cut overall system costs since it reduces inventory, part count and usually overall board size as well, but integration also helps performance. It is much easier to have to bits of logic communicate with each other at a rapid rate when they are located on the same piece of silicon. This lets SiS tweak the internal AGP bus to get more speed than separate solutions can get with the same types of logic on separate chips.

One unique feature of integrated video is that it uses system memory as video memory. This unified memory architecture reduces overall system cost but also reduces the available system memory and usually video performance as well. There are tradeoffs in every design, and in this case video performance has to be traded for overall system price, just as Intel's i815 and VIA's xM133 chipsets trade integrated video performance for price. Like Intel and VIA, SiS still offers an AGP 4x upgrade slot with their chipset, but unlike Intel and VIA, SiS still successfully sells the non-integrated version of their video as a separate solution.

The SiS630S northbridge supports 66MHz, 100MHz, and 133MHz FSB speeds. It also supports PC100 and PC133 memory. The test board SiS showed us actually supported 150MHz memory and ran with a 150MHz FSB when overclocked, which was SiS' way of showing us that the chipset had legs, but whether or not a specific motherboard will support such overclocking depends on the specific motherboard design. Unfortunately, you cannot purchase a reference design.

The SiS630S can run with any Intel or compatible FC-PGA processor, which includes the Pentium III, Celeron, and Cyrix III. We expect most boards will come bundled with a Celeron or Cyrix III processor, as these are less expensive chips that go well with the cost-saving design of the SiS630S.