Take forever to reencode or compress BD with 2 AMD Radeon Vega 64 or Radeon Pro Duo or RX 480 GPUs.
Please see attached picture below. The time just keeps counting up.

Little fruit fly
Hi ,
UHD is HEVC 4k 10bit encode, And All AMD VideoCard the best only support HEVC 4k encode, no 10bit encode.
So it will use soft, and slow.
https://www.dvdfab.cn/uhd-copy.htm?trackID=headmenu2#tech_specs For the 4K HW Acceleration to work, you need:
Either the CPUs from Intel Kaby Lake series and above;
Or, the video cards from NVIDIA GeForce GTX 1050 series and above
The fast and cheap sulution is get a gtx1050, maybe second hand for speed up.
Yours,
Wilson.