My Sapphire RX550 makes 13.5 Mh/s with 30W (gpu-z) and can make up to 14,8Mh/s.

Update my 2 rigs to 11.5.
Presently surprised. Stable and I am able to run higher memory clocks with 11.5.
Vega 44mhs 1108 core and 1120 memory, rx570 now 30.6mhs 1140 core and 2080 memory, rx550 now 14mhs  1150 core 1930 memory.
All up I gained 10mhs over 2 rigs. Could push clocks higher on 550 and 570s but not worth the extra power
Best update I have seen from clamore thanks dude keep up the great work.

570s and 550s bios modded
Latetest amd drivers.

My two RX550 runs stabel @ 13,8-14,2 MH/s on ETH. Cryptonight also about 440-460 H/s. Bios is modded.