All I will say is that the guy who was mining like mad using Vega FE apparently did his own custom XMR miner specifically for Vega. Most of the existing miners have cores written specifically for particular GPU architectures. Claymore's stuff is like that.
It's going to be awhile before we see any good mining software for Vega.
From the reddit thread about the new DAG fix drivers.
"
yuhong 1 point 2 hours ago
Worth mentioning here: "The reason performance falls off is core temp. As soon as vega gets over 60C performance falls off dramatically.
I'm currently running my Vega FE's at 1137MHz core clock and 1100MHz HBM2 clock. 55C core temp. 42.1MH/s."
"
That's a pretty nice score for a low core clock, and the power consumption shouldn't be that bad if properly undervolted. Yeah with optimized drivers and software this card may actually end up being worthwhile for mining (one the price is fixed).
https://www.reddit.com/r/EtherMining/comments/6tvp7i/amds_new_mining_block_chain_optimized_driver/