are u aware, than there is restriction, as u can use max 13gpu, then the rest MUST be mining cards, such as p104-100,...
I have this MOBO and running it with 8nvidia 5 amd without any problem
I guess newcomers think mining is easy and want to find ways to maximize profit by buying 19 gpus mining rigs, they have no idea what the hell they are doing, I suggest the op and other newcomers to read more about mining, first, mining is a hard job, second, mining is for losers, mining is only profitable on bull times but look at the gpus price, on bear times miners hardly survive, can't even pay the electricity bill with the money hehe