Alienware's M18x, Part 1: NVIDIA's GeForce GTX 580M in SLI
NVIDIA Releases GeForce GTX 580M and 570M, Brings Optimus to Hardcore Gaming Laptops - PC Perspective
Amazon.com: Valley Of The Sun New for NVIDIA GeForce GTX 580M GDDR5 2GB Graphics Video Card for Alienware M15X R1 R2 M17X R1 R2 R3 M18X R1 Gaming Laptop, MXM 3.0B VGA