Weíve already heard plenty about SiSí 648 chipset, and a whole lot of noise was made when Intel readied the i845PE with DDR333 memory support. However, VIA hasnít been nearly as vocal about its developments in Pentium 4 core logic. The P4X266 came and went, as did the P4X266A and P4X333. Perhaps performance wasnít at the same level of Intelís offerings. More likely, though, was the fact that Intel didnít believe VIA held the necessary licenses to use the Pentium 4 bus in a chipset. VIA had other ideas Ė in acquiring S3 Graphics, VIA claims to have inherited rights to the P4 bus, originally granted to S3.
VIA still doesnít hold what Intel considers the necessary P4 bus license, yet the finishing touches have been applied to its P4X400 chipset. Unlike the preceding P4X333, VIAís latest officially supports DDR400 memory, providing up to 3.2GB per second of throughput to the bandwidth-hungry Pentium 4 processor. Additionally, the board introduces AGP 8x to VIAís Pentium 4 chipset family, though the performance gain in current applications is marginal.
Then again, the P4X400 needs a strong feature set to compete with SiSí powerful 648 chipset, Intelís reliable i845 family and the dual-channel DDR chipsets that will be announced before the end of the year. There arenít many folks willing to pick a fight with The Rock and similarly, not many manufacturers want to aggravate Intel by designing a motherboard centering on a chipset Intel has not approved. VIA has consequently undertaken its own manufacturing operation, selling motherboards under the name VPSD, or VIA Platform Solutions Division. VPSDís current flagship is none other than the P4PB Ultra, a hopped up version of the P4PB 400.
The P4X400 is the first chipset to officially support DDR400 memory, contrary to VIAís prior claim that it would not support any form of DDR400 (at least until JEDEC ratified an industry specification). There are a few SiS 648 boards that will run DDR400 modules as an unofficial feature and Intel hasnít made any promises about future plans to integrate DDR400 memory support. As a result, the P4X400 enjoys a theoretical bandwidth advantage over its competition, which is especially important considering the Pentium 4ís affinity for memory throughput.
As previously mentioned, P4X400 also supports AGP 8x, first introduced in the preceding P4X333. Only a handful of graphics cards support the standard, and at this point, there arenít any games that exploit the 2.1GB per second of bandwidth offered by AGP 8x. Nevertheless, the feature gives VIA another leg up on Intelís current chipset lineup and positions the P4X400 on par with SiSí 648.