Soldato
AMD site states Typical board power (desktop) 295w for Vega 64
NVidia states tdp of 180w for the 1080 and 250w for the 1080ti (click view full specs.)
So no I wont hold on the power consumption front, you might have tweaked your card to be relatively power efficient but do not try to kid us that they are all capable of it, as loads of people have not had much luck tweaking theirs. and that is with even mentioning you put the Vega 64 up against the 1080ti..lol
Nvidia TDP has nothing to do with power consumption, is based on absolute stock core speeds.
Same applies to the Intel TDP which is calculated at base core speeds.
Go and see on reviews the difference of power consumption between eg the MSI Lightning or the Aorus Xtreme , or the SC2 & Kingpin against the FE.
The different is roughly 100W, some times even more.