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DDR400 Kills Rambus: Shooting Star SiS 648 for P4

Conclusion: SiS 648 Surprises With DDR400 And AGP 8x

The signs are auspicious - SiS might be able to land a great hit on the market with its 648 chipset. Compared to its competition (Intel and VIA), the manufacturer leads the way with numerous advantages: the 648 offers modern functions such as DDR400 support and AGP 8x, which are not to be found at all with its competitors.

Intel isn't even planning to tackle DDR400 support and AGP 8x until the start of next year. In addition, the Intel 845G chipset is only meant for DDR266 at the moment, followed by DDR333 in August.

VIA is in a different situation: the chip maker has no license for the P4 platform, which means that motherboards with the P4X400 chipset are not to be expected from the major manufactures. Also, the P4X400 reference board (final version) ran against many problems during the test, because even their hand-picked DDR400 modules didn't work with a 200 MHz memory clock.

Because SiS has obtained a license for the P4 platform, it can bring its 648 chipset to the market without anything getting in its way. Our benchmark tests show that in all categories, the SiS 648, together with DDR400 (CL2.5), is only marginally slower than the Intel 850E with Rambus (PC1066, 533 MHz). The explanation is simple: Intel hasn't changed its 850 chipset for almost two years, which pretty much means that Rambus technology will become increasingly rare.

The only real competition to expect for the SiS 648 is the Intel 845G, which is already very fast with DDR333 memory. Also, insiders are saying that SiS will soon be offering its own Rambus chipset for P4. Here, the question is whether this chipset will be able to surpass the performance of the factory-restrained Intel 850E.

The Shuttle AS45 V1.2, already equipped with the SiS 648 chipset, is especially noteworthy. In addition to DDR400 support, AGP 8x and USB2.0, there are FireWire and Serial ATA interfaces. Initial tests show that this motherboard nearly reaches the performance levels of the SiS reference board.

Our general conclusion : the SiS 648 is a reasonably priced alternative to Intel 845G, and it also offers more features. The board is garanteed to be stable. VIA remains defeated with its P4X400, which still doesn't have a license for the P4 platform.