Why Pentium 4?
If you follow this website closely, chances are you've heard of VIA Technologies. As one of AMD's most important partners, VIA has been producing the bulk of chipsets for the Athlon platform since it's KX133 chipset was introduced a little over a year ago.
Despite this, chipsets based on Intel's processors have traditionally been the company's best sellers in terms of quantity. While it owns a much larger share of the chipset market on the Athlon platform relative to its competitors (which include AMD's own 750 and 760 chipsets) the chipset market for Intel processors is considerably larger -- it's estimated that Intel controls over 75% of the desktop processor market. With Intel moving the Pentium 4 to replace the Pentium III, VIA needed a new product to support this new processor. Enter the P4X266 chipset.
Like most of the other chipsets on the market today, the P4X266 is a conventional design consisting of two chips: a North Bridge and a South Bridge. Both of these chips combined make up the P4X266 chipset. The P4X266 North Bridge handles all communication between the CPU, AGP graphics, and system memory, acting as an air traffic controller -- essentially controlling the flow of information between these components. Meanwhile, the South Bridge of the system chipset handles your USB and IDE devices and the peripheral devices you install your system, newer chipsets even offer integrated networking and audio as well.
In traditional chipset architectures, the PCI bus joined the North and South Bridge. Although with its meager 133MB/sec of bandwidth the PCI bus was slowly becoming a bottleneck.
To resolve this situation, the P4X266 chipset utilizes VIA's V-Link bus. With V-Link, bandwidth between the North Bridge and South Bridge is doubled to 266MB/sec. V-Link is also used on VIA's other DDR chipsets such as the KT266 (for AMD systems) and Apollo Pro 266 (for Intel systems). Intel also offers a similar feature on all of its 800-series chipsets.
The P4X266 chipset