At issue is the performance of NVIDIA's Vista drivers. There are numerous posts in NVIDIA's forums commenting on the state of the company's Vista drivers. Part of the problem comes from how NVIDIA is marketing their graphics cards. The product page for the GeForce 8800—NVIDIA's top-of-the-line card—says that the GeForce 8 series GPUs offer "full support" for DirectX 10, but the picture is a bit muddier than that. The latest beta drivers—ForceWare v100.59—still leave those with SLI configurations out in the cold when it comes to DirectX 10, limiting DirectX 10 support solely to single-GPU 8800 systems."