Pointless, been there done that GPU mining rigs European supplier London based Vega RX580 NVIDIA 1070 1080Ti single mining rig to farm setup (part of that thousands $$$$ spent in R&D I did)
Mobo BIOS have limitation due to PCIE resources (12 GPU max on server class motherboards that costs $100’s. Cheap mobo from $50 to $400 only allow for 7 or 8 GPU max) Remove 8 GPU limit on OpenCL driver - AMD Community
GPU drivers have limitations
Regular Windows (non Enterprise) have limitations
I have a bunch of those splitters if someone like to try for themselves http://www.ebay.co.uk/itm/182310350018