I dont think I need something special. People are putting 2 or 4 gpu cards in one slot. They have some kind of hardware is making from 1 pci -> 2 or 4 usb + risers what u think ?
That's possible and runs off of splitting one 16x into 4x4x or something like that, but those adapters are real expensive from what I see on some websites and it's better to just buy more motherboards than to take all the time and hassle to do something so small.