Premiere Pro 390X
Your sapphire tri-x 390x should not experience any issues during video editing in Premiere Pro.
studying ATM processes
Check the guide and scroll to Windows OpenCL—you should be able to adjust a file so your 390x works just like NVIDIA cards.
It seems 290x is compatible, but 390x might not work. You should verify the specific requirements for each resolution.
This feature needs to be enabled for 390x but it's currently restricted to CC only.
I confirmed I might be receiving a copy.