that's just the core at 82w, the vrm uses another 70w..check it with aida64
my rx570 elpida @ 900mV uses about 150w for solo 28MH/s eth with core on 1132MHz, mem on 1975MHz..and 180w for dual 28MH/s eth + 280MH/s pasc
I download Aida64 and checked the power consumption of the GPU and VRM and it doesn't seem to make sense. I raised to the voltage to a little bit under stock voltage ~0.962v just to see how much power this would consume and Aida64 is saying the GPU is using ~115 watts and the VRM is using ~93 watts. But I highly doubt that means the cards are using 115 + 93 = 208 watts? That can't be. Which means at default voltage this card would be using way over 200 watts which it shouldn't since its TDP is only 150 watts. You sure the VRM wattage isn't just a percentage of the GPU wattage?
http://i.imgur.com/GFSBxKw.png