I have rig with 4x RX580 Nitro+ 8GB.
Yesterday I installed AMD Blockchain drivers and my hashrate raised from 26MH/s to 31MH/s.
I am dualmining ETH + SIA.
It is fine, but power consumption raised too. Entire rig pulls about 650W now and after cca 12hrs crashes, but shares are 100%.
What settings do you have? I use cvddc a mvddc at 850, gpu 1250MHz, ram 2200MHz.