Dear friends i have 6 pieces Sapphire RX 580 8 Gb Nitro+ oc ve 2 pieces RX 570 nitro+ oc 8 gb gpu cards.
3 of them has RX 580 has hynix ram and others have micron ram. ı can get 17-18 mh ffor mining ETC at stock and 19-21 mh or ETH.
Also RX 570 has Hynix ram. I tried to mod at RX 570, their mining value decrease to 16 from 18  mh.after that i tried a rom from web i took 20 mh now for RX 570 at ETC.
For RX 580 micron ram modded and i took to 19 mh from 17 mh.
But i tried to mod RX 580 Hynix ram version, i took failure 512 kb. so i wanted to try another rom but saw the same fault.
For RX 580 hynix ioundd a rom from web.but i saw a new fault messsage about this cards "your rom doesnt delete"
i think these cards nclude silent swich button.What is these i have no idea.

PLEASE HELP ME!THANKS TO EVERYONE