I saw the Help section before and used RX580 OC settings on my RX570

the funniest thing happened on Claymore 11.5 mining ETH

i used Core Mhz 1130
Memory 2125 ( crashes with anything more than that )
Undervolting 975

and i was getting constant 26-27 MH per card

then i tried to use lower power outage which was on 6

as i go lower the Hash increases which i don't know why is that, anyway on 3 i got 30 MH stable rig

can some one explain why thats happening ?

hope it helps some one else