How long have you been around computers to ask that question! Everyone knows the 1080TI didn't have G-sync, but I still can have 120hz @4k on my GPU and OLED
Like I said - I rather have the best OLED monitor on the market than have a powerful GPU for only 1080p LCD gaming!
The CX/C1 is only HDMI 2.1/2.0 no DP port
All you have to do is set the TV to PC mode in Nvidia control panel 120hz - 4.2.0, @4K 8bit also turn the OLED light to 40/50 on the TV settings I have mine @35 and Brightness 40 the choice is yours but I gaming in a low light room, the blacks are ink black in games also movies and the IQ is at it's best on the market no LCD/LED monitor can beat it's IQ the C1 is the new model 2021 next April it will be the C2 it changes every year to a new model with small upgrades
Tip is to mix your content between games and streaming. leave all the Anti-burn in features turn on and turn on HDMI Ultra HD Deep colour on the TV settings also logo luminance to = High Auto power off I have mine set to 6hours you can turn it off your choice, I only use my OLED 12hours a day but thats me