Everything I've seen boasting greater than 54Mh/s have been changing the OpenCL worksize and causing invalid shares that reduce effective hashrate back down to around 50-54Mh/s.
Exactly that. 1300/915@0.85 gives solid 51.5mh/s. If you increase worksize then reject rate increases to 10-20%
@claymore
Strange stuff regarding 380 hashrate reporting with v15. Just updated drivers from 18.6.2 to 19.10.1 and miner reports 380 hashrate at 37mh/s+.
Phoenix is still fine with ~19mh/s, which is the true hashrate of the device.
Fury hashrate reporting is fine. Not sure if it happened with earlier versions of the miner or previous 19.x drivers.