Badly stung from its P3 chipset disaster, Intel tightened the licensing rules and restrictions for third-party chipset manufacturers wanting to build solutions for P4 CPU's, and although SiS, ALI, and ATI all capitulated and signed agreements to pay Intel licensing fees for every chipset manufactured, VIA held out. Several years earlier VIA had purchased the video card designer S3, which had several cross-licensing agreements with Intel. According to VIA, these agreements were sufficiently broad to give the Taiwanese chipset manufacturer the right to produce P4-compatible chipsets without paying royalties. According to Intel (unsurprisingly) they were not.

When VIA moved to introduce their own P4 compatible chipsets (P4X266 and P4M266) Intel promptly slapped them with a series of lawsuits across multiple countries. VIA promptly counter-sued, but the damage was done. With VIA involved in a battle over chipset patents, motherboard manufacturers were much less willing to build or promote boards based on the manufacturer's standards.