hey, do you find any solution for you issue? i have the same problem, i have 4 Rigs, all with z97 Asrock Extreme 4 and 5 x Msi Radeon rx 480 8GB p/rig , and all rigs detect 4 gpu Correctly, in sometimes windows get the 5 gpu... but the windows is very innestable, the same with simpleming or EthOS, the problem is in the hardware..... Any can help us?