I've been doing a lot of research recently and I've found the new $800 RX VEGA can do up to 41 MH/s @ 300W.
Whoever the AMD CEO is she needs to stripped naked, tied to a post and publically caned with one lash for every MH/s under 80 MH/s and one lash for every Watt over 200W.
First it was not amd claims, second from badwitch calculation vega is capable do 80 MH/s and i think big mining farms have optimized miner (cause vega rx was sold out in first days even if is poor in gaming) , I think Claymore have asm for vega but just deley it for big mining farms sake ... It is business...