Performance is about the same, but the AMD blockchain drivers have an 8 card limit. The Crimson Relive 17.11.x and Adrenalin 17.12.x drivers let you run at least 13 cards and are compatible with the Windows 10 v1709 fall creators update.
Maybe you can tell : Adrenalin 17.12.x can handle 14 cards under windows ?
Many people report the motherboards won't POST with 14 or more GPU's. I believe 13 AMD cards is the current limit under Windows v1709. My ASRock H110 Pro BTC+ works fine with 13 RX 580 under Windows v1709 with the 17.12.2 drivers.