I mentioned elsewhere that if two RX480's are roughly equal to a 1080 in AotS dx12, then 2x RX480's are roughly equal to a 1070 in dx11 (more or less depending on the game) because a pair benches 5-15% faster than the Fury X going by AMD's presentation. It is also similar price wise, with the added dx12 performance, at the cost of CF frame times.