Rambus has scored a big win in the ongoing patent-infringement lawsuit it filed with the U.S. International Trade Commission against Nvidia. The case dates back to July 2008, when Rambus accused the graphics firm of violating 17 of its patents and asked for an exclusion order barring the importation and sale of concerned products. Over the years, many of those claims were either dropped by Rambus or terminated by the ITC. But last January, of the five patent claims still determined valid, Nvidia and several of its OEM partners were found guilty of infringement on three.

Today that ruling has been upheld. The ITC has not yet posted details on its website and Rambus said the final determination has yet to be released, but the company expects the ITC to issue a ban on imports of several Nvidia products. The ban would presumably extend to many third-party products that integrate Nvidia components, such as motherboards and pre-built PCs. But Nvidia seems confident that partners will be able to continue sales by taking advantage of a licensing arrangement Rambus reached with European regulators as part of an unrelated antitrust case.

Nvidia has previously suggested it would consider paying Rambus to license the technology if the ITC ruled against them. For now, however, the graphics firm says they will appeal the case in the Federal Circuit Court of Appeals and make other moves to avoid any sales or import issues.

Rambus said to be "extremely pleased with the ITC's decision" as it confirms the "value of [their] patented inventions." The company doesn't really build much these days, but has spent more than a decade suing computer-memory chipmakers that refused licensing deals. Just last year the company got about 96% of its $113 million in revenue from patent licensing royalties, and in January 2010 it reached a milestone settlement with Samsung for around $900 million.