https://www.anandtech.com/show/13210...on-pro-wx-8200
Apparently Hynix was the original choice for AMD like with their previous gen but were forced to go with Samsung instead. From what I read Hynix was meant to be more cost effective but I don't know now as Hynix were meant to have it available early last year IIRC,and apparently that is why Vega was so delayed!