NVIDIA shows off fastest Notebook GPU. On Tuesday, the graphics chip-maker announced the NVIDIA GeForce GTX 580M, the fastest graphics processing unit (GPU) for notebooks. It is featured now in the Alienware M18x (pictured). "The best game support. The best gaming features. The best gaming performance available anywhere. That's the essence of the GeForce GTX 580M," said Rene Haas, ...