What is the point of having HDMI 2.1 outputs when all the inputs are HDMI 2.0?

[Ninjo]

It is my understanding that HDMI 2.1 supports up to 48Gbps of bandwidth allowing for uncompressed 8k and higher quality audio. But isn't that pointless if your HDMI 2.1 source component is plugged into your receiver/processor that only has HDMI 2.0 inputs that can only handle 18Gbps of bandwidth? Thus limiting more or better audio streams.

The only reason I can think of is using eARC to send the data back to the processor from the TV. If I'm wrong here or confused about how it works can someone please set me straight.

 

[HarmonicTHD]

It is my understanding that HDMI 2.1 supports up to 48Gbps of bandwidth allowing for uncompressed 8k and higher quality audio. But isn't that pointless if your HDMI 2.1 source component is plugged into your receiver/processor that only has HDMI 2.0 inputs that can only handle 18Gbps of bandwidth? Thus limiting more or better audio streams.

The only reason I can think of is using eARC to send the data back to the processor from the TV. If I'm wrong here or confused about how it works can someone please set me straight.

Yes that would be pointless. However, high quality audio doesn’t need 2.1. You only need 2.1 if you watch 8K, 4K/120hz movies. The newer Denons seem to support 2.1.

 

[gags11]

It is my understanding that HDMI 2.1 supports up to 48Gbps of bandwidth allowing for uncompressed 8k and higher quality audio. But isn't that pointless if your HDMI 2.1 source component is plugged into your receiver/processor that only has HDMI 2.0 inputs that can only handle 18Gbps of bandwidth? Thus limiting more or better audio streams.

The only reason I can think of is using eARC to send the data back to the processor from the TV. If I'm wrong here or confused about how it works can someone please set me straight.

Which receiver are you referring to. I was just checking Pioneer LX-505 and it looks like HDMI inputs are also 2.1

 

[Ninjo]

Which receiver are you referring to. I was just checking Pioneer LX-505 and it looks like HDMI inputs are also 2.1


View attachment 238879

Ok now I'm feeling a little silly, when I go back and check the specs all inputs appear to be 2.1 on the processors I was viewing from JBL, Anthem, and Arcam.

 

[HarmonicTHD]

Ok now I'm feeling a little silly, when I go back and check the specs all inputs appear to be 2.1 on the processors I was viewing from JBL, Anthem, and Arcam.

Be careful and read up on it. The implementation of the 2.1 standard is somewhat flaky at times. Not all can eg do PS5 2.1 in.

 

[SupremeAV]

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

 

[srrxr71]

There can be. You can get an Nvidia card to output 12 bit 4:4:4 color at 120fps. It will do it but the 40gbps TVs can only handle 10bit 4:4:4 at 120fps. It’s not a huge deal but 48bps is more future proof I guess. It’s bad how LG dropped back to 40gbps but it’s not a huge deal.

 

[srrxr71]

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.

 

[JSmith]

Thus limiting more or better audio streams.

There are audio streams that use more than 18Gbps bandwidth? Must be a very high bitrate...


JSmith

 

[srrxr71]

There are audio streams that use more than 18Gbps bandwidth? Must be a very high bitrate...


JSmith

In the hdmi explanation thread it says there can be no audio without video in HDMI. There must be video even if it’s basically blank because the audio sits in the unused part of the video signal.

I guess what he means is that HDMI 2.1 is needed to have enough overall bandwidth for eARC to work. In other words to have enough feee space to allow for higher quality audio streams than HDMI 2.0.