public miner does 4mhs @ 109W (60%tdp) gtx1080
So you are saying that the higher model, more expenisve card is only 3.8% faster than on the gtx 1070 with the sp-mod?
It is 50% more efficient with only 10% price gap. One can spend 0.05btc better to buy gtx1080 or rx vega56 instead of buying gtx1070 and paying you. And will get much more profit with lower power consumption ))