The Hyper M.2 X16 Gen 4 card takes RAID performance to the next level - Edge Up
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.co.uk: Computers
PNY NVIDIA NVS 300 512MB GDDR3 PCI Express Gen 2 x16 DMS-59 to Dual DVI-I SL or VGA Profesional Business Graphics Board, VCNVX300X16-PB : Amazon.co.uk: Computers & Accessories
PCI Express - Wikipedia
Guide to PCIe Lanes: How many do you need for your workload?