When I put the internal GPU to PCIe slot No. I used a Cyclone host bus adapter card 426, a Cyclone backplane 427, a Molex cable 2m, a BeQuiet case and a BeQuiet 1200W PSU. I needed more GPU power for 3D rendering, so I decided to build this expansion box according to hoevelers instructions. I'm using the Mac Pro for graphic design and Blender 3D rendering running Mavericks and El Capitan.
I am working with a Mac Pro 5.1, dual X5690, 96GB RAM, 512GB AHCI SSD, with 3 monitors attached. Just wanted to share my experience with this setup.
