Claymore how is this explained , this 48.5 mgh is one rx480 which was hashing before with 28.5 mgh , now it is 48.5 , obviously it is not real , but it is hashing for hour with no errors and even after restart of the miner it is the same , even dual mining? Could it be this samsung ddr that when clocked lies the miner that it hashes fast , but in reality it is not , that is why effective hashrate is lower 30% ! I see on all my machines with samsung ddr that has this low effective hashrate! The micron ones and the r9 390 machines don`t have this low effective hashrate!
Of course this is not real hashrate for RX480. Probably you modified bios/clocks too much and now that card is crazy.
Actually it is the same bios and same setting for over a month , may be a windows update made it crazy like this! Just wondering why there no errors and even hwinfo don`t detect gpu errors! Very strange?