supposedly none? theoretically all?
Reasoning is that while Vega's could crunch a lot of numbers, 99.9% of miners are also concerned about power usage since that affects profitability a lot. and no, 300W+ is not looking pretty in there.
Vega, 30 to 35MH/s, power usage 350W,
Rx480, 25MH/s power usage 150W,
as you see, it's "better" but it also "costs" more and eats more power/hash so.. less profitable.