AMD uses some serious high power draining RAM modules, actually the reason 1060 isn't using as much power is because it's 2 GB shy. A true 4GB model of the 480x should use as much or around the same as the 1060. DDR5 drains a lot. Most of the power savings in the new cards 1070 and 1080 are because of the DDR5x. Considering the Fury cards are devastating the 1070 in DX12 titles that utilize DX12 features and not just render it's good enough to say that AMD's equipment hasn't quite been tapped effectively yet.