I got a single RX 470 MSI Armor edition, core clocked to 1400MHz and memory to 2145MHz, +50% limit power, Voltage parameteres on Auto. Using Wattman, drivers 19.8.1. Card reaches its max power (127w).
I use nicehash to mine, I get about 45mh/s mining Lyra2rev3, and sometimes it switches to phoenixminer and does 22mh/s, using above 100w. But then, after like 3-4 minutes, it caps at 90W and does only 11Mhs, so it auto-switches back to TeamRedMiner (lyra2rev3). Is this a bug or does the programs limits the card to 90W for some reason?
Note* Card reaches 127W with full load on other miners as well.
Normal behavior with Phoenix Miner. In fact the drivers hangs so the hasrate is reduced.
With Phoenix Miner and good settings you can reach +30Mh/s depending your memory.
My settings : 1140 MHz@900mV for GPU, 2040 MHz and if you put the RXBoost option with AMDTweakMemory you get extra h/s normally your GPU will be around 75 W.