I just built a computer, this last Christmas. Intel processor, 32 gb ram, GEforce 4 gb video,...windows 10, no issues....run 4k video from my go pro, while playing company of heros 2, online.
I build systems, also. i play a lot of online games. I am also a computer engineer...software and hardware.
the AMD FX-8320 chip that you are using, does not do very well with 4k video, it is hit/miss.