nVIDIA's PCI-Express Product Line
nVIDIA offers two distinct families of GPUs in its PCI-Express product line for desktop PCs:
GeForce 6 (bridged and native PCI-Express GPUs with advanced Shader Model 3.0 support for DirectX 9.0c)
GeForce PCX (adapted from the GeForce FX line of GPUs for AGP with the HSI chip)
Shader Model 3.0, introduced with DirectX 9.0c, supports much more complex vertex and pixel shader programs than in previous DirectX 9 versions. As usual, it will be some time before 3D games adopt all of DirectX 9.0c features, but supporting the very latest version of DirectX helps to 'future-proof' a GPU.