I have a similar issue. With a Sapphire ITX RX470, I only get around 22 MH/s at stock speed and maybe 23 Mh/s with memory up to 2000. How much would other memory timings / BIOS mod affect the result? I've read about people getting up tp 30 Mh/s out of a RX470, is this also possible for RX570, and is this only becuase of the changed memory timings?!?
A modded bios is definitly required if u want to get anything over 26mhs. If u dont want to do bios mod buy gtx 1070s. These u can just adjust with msi afterburner and u be at 30mhs after u click the mouse