Mountain View (CA) - Silicon Graphics Incorporated (SGI) announced Monday that it has filed a patent infringement suit against graphics processor manufacturer ATI in a Wisconsin US District Court.

The lawsuit alleges that ATI’s Radeon brand of graphics processing units (GPU) infringe upon SGI’s patent, numbered 6,650,327. SGI said that it is asking for an unspecified amount of monetary damages, in addition to an injunction to prevent ATI from selling any more Radeon processors.

The patent, which was issued to SGI on 18 November 2003, claims intellectual rights for "A floating point rasterization and frame buffer in a computer system graphics program," as well as "the rasterization, fog, lighting, texturing, blending, and antialiasing processes operate on floating point values," which ATI has allegedly used without SGI’s approval, according to the lawsuit.

SGI works with ATI’s competitors, including Nvidia, which makes them understandably upset about the prospect of ATI copying off of their proprietary technology. "SGI has licensed this technology to ATI’s major competitors and, as I have previously been stating publicly, that SGI intends to aggressively protect and enforce its IP. This is the first visible step in that process," said SGI’s CEO Dennis McKenna.