Via claims that Intel's Pentium 4 processors "infringe, contribute to the infringement of, or induce others to infringe" a Via patent that concerns "different formats in which numeric data may be stored in a microprocessor." The intellectual property (U.S. Patent No. 6,253,311) in question is co-owned by Via and Centaur Technology, a wholly owned subsidiary of Via that handles its microprocessor design.

"Via . . . is becoming an important supplier of PC microprocessors, thanks to the hard work of our CPU designers in Texas," said Richard Brown, marketing director at Via, in a statement. "Filing this lawsuit is the first step in protecting our intellectual-property rights."

Earlier this month, Intel filed suit in Delaware claiming that Via infringed several Intel patents in the development of its P4x266, a Pentium 4-compatible core logic chip set that supports double-data-rate SDRAM. Intel has not issued Via a bus license for the product, but has granted licenses to Via's top competitors — Silicon Integrated Systems (SiS) and Acer Laboratories.

Via claims that it doesn't need a new bus license because of an earlier cross-licensing agreement — between Intel and the former S3 Inc., which Via now owns.

The Via lawsuit is believed to be a reaction to Intel's legal strike. There is little love lost between the companies, which have clashed before over IP concerning the Pentium III The two companies settled that suit out of court in 1999, allowing Via to build market share on its popular PC133 chip sets while Intel stuck with its Rambus-based products. At the time, motherboard makers in Taiwan were buying Via's SDRAM-compatible products because the more expensive Rambus DRAM was unpopular with cost-conscious system houses here.

But the situation is quite different now, with top-tier motherboard makers very reluctant to buy the DDR chip set and offend Intel. "There might be a shortage of Socket 478 Pentiums, so people don't want to risk their relationship with Intel," said a source at a tier-one motherboard company. "Intel has told us that they will supply us [with CPUs] if our customers have trouble getting them through their regular channels, so a close relationship with Intel benefits us."

The P4x266 handily eclipses the performance of Intel's first Pentium 4 chip set, the i845, which is a single-data-rate product. But that isn't enough to budge the major board makers; though some of the second- and third-tier players are using the P4x266. Intel is expected to launch its DDR product soon, with a possible announcement coming in November.

No matter the outcome, Via's window of opportunity for the Pentium 4 chip set may be shrinking. With motherboard makers unwilling to break ranks with Intel, Via's jump on its competitors is waning. "Intel will keep its DDR chip set pricing competitive with Via, so we may just stick with Intel. If we want something cheaper, maybe we'll go with the SiS solution," the source said.