You are totally wrong , incorrect !!! And probably talking about something you don't have any experience 
You dont need any trick to use more than 8 AMD or Nvida gpus on one system under windows ......
You dont need any trick to use more than 8 AMD or Nvida gpus on one system under windows ......It's not about putting your cards more than 8, and run smoothly without problems, right? even many posts here about getting trouble with the only 5-6 card. Picking the drivers, Patching etc, it is isn't trick? Sound like, you just plug and mining smoothly.