Non-gaming power consumption is pretty much the same as the AMD reference design. Single monitor idle power is great, but Navi's multi-monitor power consumption is still too high when compared to that of competing NVIDIA cards.
Gaming power consumption is around 20 W higher than the AMD reference design, which is expected given the increased clock speeds out of the box. Around 250 W for the graphics card is very reasonable and easy to handle for nearly all power supplies.
Recommended PSU: 500 W