Amazon.com: NVIDIA Quadro 4000 for Mac by PNY 2GB GDDR5 PCI Express Gen 2 x16 DVI-I DL, DisplayPort and Stereo OpenGL, DirectX (Boot Camp), CUDA and OpenCL Profesional Graphics Board, VCQ4000MAC-PB :
nVidia Quadro 4000 2GB Graphics Video Card for Mac Pro Dual DVI CUDA : Amazon.co.uk: Computers & Accessories