My new Marantz Cinema 50 seems to support 48gbps... I have an LG C2 OLED but from what I understand there is no source outputting full 48gbps including the PS5. The source connect when I took this screen shot is a 2021 Apple TV 4K
So apparently the Apple TV is HDMI 2.1 but implements only one feature from it: eARC.
As stated here:
https://www.reddit.com/r/appletv/comments/w90ii6
Even the new one is no different:
https://www.reddit.com/r/appletv/comments/yggjdy
Apple is so backwards on this it’s crazy. Even the Mac Mini M1 doesn’t support any HDMI 2.1 features via a DP to HDMI 2.1 cable. It will support those some of those features when connected to a certain one of its own overpriced monitors. Everyone else can deal with it I suppose.
I cannot even run 4:4:4 color with HDR. It’s pretty bad so effectively I cannot use HDR with a Mac because 4:2:2 is fine for video but unacceptable for text. No big loss - I don’t enjoy Mac OS either and the Mac mini is holding down some paper here.
Really even for 4k Blu Ray it’s not needed. It’s 4:2:2 video so no issues.
I use a PC as my main source so I keep the TV on RGB color (same bandwidth as 4:4:4) HDR and 120fps just because I can. I guess i get better scrolling? LG has supported this for years so they set the bar. No reason for everyone else to drag their feet for about half a decade by now.
Having said all that I would not buy anything in 2022 without supporting it properly. It’s really time for everyone to get on the same page with HDMI 2.1.