I built my PC in 2012 and it runs 1080p at 60Hz and 4K and 30Hz (nVidia GeForce GTX 690).
In 2012 I assumed I would upgrade to 4K at 120Hz in 3 or 4 years.
So, 8 years later I'm still waiting. I guess DisplayPort 2.0 and HDR 4k at 120Hz will be available in 1 or 2 more years.
Wow, I just can't believe how slow technology evolves.