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 :
Amazon.com: HP 671137-001 NVIDIA Quadro 4000 PCIe 2.0 x16 graphics card - With 2GB GDDR5 SDRAM memory : Electronics
NVIDIA Quadro 4000 2GB GDDR5 Video Card VCQ4000-PB
Nvidia Quadro 4000 vs Nvidia Quadro K4000: What is the difference?