Rambus has asked the International Trade Commission to terminate an investigation of Nvidia relating to four patents as part of a November 2008 complaint.
Rambus provides high-speed memory interface technology, though in recent years the company has become better-known for intellectual property litigation practices. Rambus has sued many of the world's largest chip manufacturers.
The Los Altos, Calif.-based company conceded before the ITC that Nvidia products do not infringe on its four patents, and also asked for termination of several claims from a fifth patent in the ITC action, according to an Nvidia statement.
"We are pleased Rambus has recognized the weakness of these patents and claims," said David Shannon, Nvidia executive vice president and general counsel in a statement. "These withdrawals represent essentially half of the patents and one third of the claims asserted against us, and we look forward to addressing the remainder of the case."
The current ITC litigation originally included nine patents involving memory controllers related to graphics processors.
In June, Nvidia announced that the U.S. Patent and Trademark Office had rejected 41 claims, in seven patents, which Rambus had asserted in the ITC action against NVIDIA.
Rambus has a checkered track record on lawsuits. The European Commission launched antitrust investigations against Rambus in 2007, alleging intentional deceptive conduct in the context of the standard-setting process, citing its behavior as "patent ambush."
In January, a Delaware federal judge ruled that Rambus could not enforce patents against Micron Technology. Judge Sue L. Robinson, in the U.S. District Court in Delaware, ruled on January 9 that evidence "spoliation" occurred when Rambus allegedly destroyed important information related to the case that could be used against it. Robinson's decision rendered Rambus' patents unenforceable.