125W is too much, my rx 580(Red Dragon V2 8gb Micron) are consumpting 90-100W with hashrate 29-31mh/s.
I have newer cards with bad memory, i run them at 29mh/s
And some older cards with better memory with 31mh/s.
I think, i can help you to mod your bios or i can send mine bioses, one should fit. If you are running 30mh/s already, maybe yours are one of those, that can run at 31 mh/s
you can contact me: aesleep@ya.ru