I recently purchased a LG OLED C2 TV, which supports 4k120Hz but only has HDMI 2.1 ports. I am aware of HDMI 2.1 being an issue on AMD, even though my GPU is Nvidia (RTX 3060Ti) I want to switch to AMD in the future, so I opted to invest in an AMD-friendly setup. I purchased the Cable Matters active DisplayPort -> HDMI 2.1 converter mentioned in this Reddit thread, which purportedly can do 4k120. However, when I change it from the default 4k60 modeline to 4k120, the TV shows a “no signal” message. In fact, to get 120Hz I need to drop the resolution down to 1440p.
Even though I’m not going for VRR (yet), I also tried flashing the VRR-enabled “Spyder” firmware just in case it fixes the refresh rate (it does not). I tested every DP port on the 3060Ti as well, with no changes. What might I be doing wrong?
I have the same TV. It doesn’t specifically help you but using HDMI 2.1 sources works fine for 4K HDR 120Hz and VRR. I have too many devices (Xbox Series, PS5, AppleTV, Switch) so they are routed through a GUIDE3 switcher.
So I would think it is the DP converter or the HDMI cable not really being 2.1.