The U.S. District Court for the Northern District of California has dismissed a class action suit against NVIDIA that accused the company of trying to hide its knowledge of defects in a line of graphics chips, in order to keep the stock price up.

In a strongly-worded opinion, Judge Richard Seeborg said the plaintiffs did not establish that there was any evidence that the company knew that its chips were defective. Further, the opinion notes that some of the evidence presented by witnesses was from people who did not work at the company and were not in a position to know if the chips were defective or not.

Judge Seeborg gave the plaintiffs 30 days to file an amended complaint, or have it dismissed and the plaintiffs barred from re-filing another suit.

The original lawsuit was filed in 2008, by Lisa Miller, and the class action suit eventually included two union pension funds and the retirement fund of the city of Pontiac, Mich. The suit covered those who bought NVIDIA's stock between Nov.2, 2007 and July 2, 2008.