NVIDIA GeForce GTX 1080 Ti and 4k 120hz on LG OLED48CX (over HDMI)

There's a lot of confusion out there on what resolutions / refresh rate / HDR (on) / g-sync (on) combinations can be achieved on the GTX 10 series. Particularly as the LG CX range of OLED TV's have been out for a while and have proved they are very capable as monitor level displays for gamers.

The DisplayPort 1.4 output from the 1080ti can do 4k and 120hz. The HDMI 2.0 output is supposedly capped at 4k 60hz. Most TV's haven't adopted DisplayPort so you are stuck with having to use HDMI, this is no different for the LG CX range of TV's.

However if you get hold of a HDMI 2.1 cable (or one that can push the bandwidth required) you can at least get an LG CX TV receiving a 4k/120hz signal to the desktop, with a sacrifice of losing HDR and RGB colour. Oh and G-sync won't work either!

When you launch a game however expect the game resolution offered to probably be 1440p maximum. So ultimately you AREN'T going to be able to game at 4k 12h0z, but I think it all depends on the game.