I see that there is a new open-source miner for Lyra2REv2 on AMD cards now:
https://github.com/CryptoGraphics/lyclMinerPerformance seems better for me too 10%-15% faster at same settings on my Vega 64 cards, is mkxminer gonna be updated with code from this?
What hashrates and power draw are you getting? This miner keeps freezing my cards, wonder if I need to optimize or the miner is just buggy