Rx 5700 Asus Reference after copying 1500 timing straps I now get 57Mh PheonixMiner Ether on HiveOS with CORE 1375 CoreV 800 MEM915 Miner Reporting 118 watts
57 is too high, check for errors or bad shares. Its not point running too high a clock / too tight a strap if you do not end up getting a benefit.
For accurate measurements check poolside stats over 24 hours to get to know if a change (overclock or strap change) had any benefit.
57 is fine. 3 out of 4 of my cards are doing 59+ stable, confirmed hashrate at pool side.