HDMI is the newest and greatest standard. It will allow for 4k @ 120Hd (4:4:4) with dynamic HDR and Variable Refresh Rate (VRR). We are years away from gaming at 8k but 4k with HDR @ 120Hz is a big deal. As monitors are not often upgraded I would like my next monitor to have these feature, even if I don't initially have the GPU power to push past 60 fps. When should these appear in the market. Also, how with VRR stack up against freesync. I read a long time ago that something like freesync would be coming to HDMI. This would be great to have a freesync like tech supported by both green and red, that didn't bring up the price of monitors substantially. techradar pcgamesn engadget
2018. The first 4K monitors with a refresh rate above 60hz have been announced a while ago, then delayed to 2018. http://www.pcgamer.com/asus-and-acer-delay-feature-rich-4k-144hz-monitors-with-hdr-until-2018/ Some thing applies to the 3440x1440 200hz HDR screens.
Belkin Ultra High Speed 4K HDMI Cable (2m) Bandwidth up to 48 Gbps It seems that apple has started selling a HDMI 2.1 cable
Aside from games that are based on rather basic game engine mechanics and physics, I think we are still some way off GPUs that can utilize a high refresh rate 4k panel. I'm running a 1080ti with an ASUS PG279Q which can do 165hz. I also have a 40" 4k monitor which I think is a necessary size for that level of detail, having run the two side by side. When in game I see very little appreciable difference in graphics detail between to two monitors and would take the ASUS any day of the week. That's not to say that the move forward isn't worthwhile however.
Some of the better optimized games like for example Doom or BF1 easily hit 60FPS @4K on a single 1080ti, so we aren't that far away from being able to make use of 4K monitors above 60hz even with modern games, of course if it has to jump straight up to 144hz or if maybe lets say 100hz would have been enough as a first step is a different question.
I can get the monitor and worry about GPU support later. I keeps displays for at least 5 years, in the time I'm likely to go through a few GPU upgrades.
Problem is in the PC space none of this stuff will get adopted or work properly for years, how ropey is Windows with 4k60HDR, whereas the TV and games consoles are quite happy 40 odd inch 4k with do me as a gamer and for work purposes, any higher on the DPI and I would struggle to read the text a comfortable distance from the screen, extra refresh rate would be welcome but actually having used the adaptive tech I would say that is more important. Hope the GPU vendors ditch proprietary solutions for this. A wrap around screen setup could be quite interesting with a good curve though and lots of pixels as a single monitor with the extra bandwidth.