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NVIDIA Quadro 4000 by PNY 2GB GDDR5 PCI Express Gen 2 x16 DVI-I DL, Dual DisplayPort and Stereo OpenGL, DirectX, CUDA, and OpenCL Profesional Graphics Board, VCQ4000-PB - Newegg.com
Ars Reviews the Quadro 4000 Mac Edition: NVIDIA's sole Mac offering a promising start | Ars Technica
Amazon.com: Nvidia Quadro 4000 2GB GDDR5 256-bit PCI Express 2.0 x16 Full Height Video Card with Rear Bracket (Renewed) : Electronics