This cards have all bad coolers. Look
https://www.reddit.com/r/Amd/comments/9eqhnc/my_vega_64_le_was_having_horrific_throttling/

On 4 my vegas i changed cooler to watercooler because of this, 3*56 and one limited edition 64.
Solder was all over the place when i opened them up. All survived, mounted cpu water coolers on them and on one mounted accelero 3 air cooler. All coolers performed much better then original vapor chamber.
The card was set to max 65c and 4900rpm and original coolers still has melted. So original coolers are bad.
Even the 120mm radiator water cpu cooler is beter then vapor chamber (much lower temps). For my 4th card i intend to buy 240mm aio cpu cooler to test it out

And all my cards are set to.
P7 is at 1408:900
Mem3 is at 1100:880
Samsung memory