Hello, many people are having problems with getting the new Rx 570 cards to work properly (256kb bios).
I have much experience with them, can help you get the optimal hashrate/power usage for your cards and general mining related questions/advices.
You should get (without the new beta driver that fixes the polaris hashrate) about 29.8 MH/s with medium power usage or 27.6 MH/s with powersave mode.
I have many Gtx 1060/70, so I can help with them too.
Add me on Skype: bijac666 or FB:
https://www.facebook.com/bijac666