I always used rx 480 cards for my builds in the past , few days ago received my first rx 470 nitro cards order for my new build.
My first priority was optimizing the bios for ETH mining with low power consumption and high MH/s
GPU-z reporting 75.6 watts , the card real wattage is around 100-110 watts / card .
( Test bench idle power draw at the wall 68-72 watts , with gpu hashing total wattage is 170-175 watts at the wall )
I was able to push the card to the 29.5-29.8 MH/s range , with much more power draw , but never checked the stability on that speed , it was running for 15-20 minutes without any problem .
Played with the bios / timing / voltage , created a modded bios , there is my result :
If im not using the computer to taking screenshot's the hash rate is stable in the 29.2-29.4 MH/s range