Nvidia and Rambus are in a patent tussle
 

According to Reuters, the alleged infringements concern patents that Rambus claims Nvidia used without licence or consent. The USPTO was split on the legal dispute and ruled that one Rambus patent had been infringed, another claim was decided in Nvidia's favour, while a third received a mixed verdict.

The patents relate to a memory controller in one of Nvidia's graphics processors. Naturally, Nvidia will appeal, but if the ruling is confirmed it will probably have to cease shipping the product.

http://www.theinquirer.net/inquirer/...-patent-tussle