Will the upcoming HDMI 2.1 gaming monitors support 4k at 144hz on PC with the HDMI 2.1 port?

[p0tat0stix]

I have searched far and wide for this specific answer, and the only specs I see listed so far seem to be that the new HDMI 2.1 gaming monitors will support 4k @ 120hz. It seems to me from the research I've done that HDMI 2.1 can easily support 4k @ 144hz from a bandwidth perspective, but nobody is listing that as an option. Why are they all settling on marketing 120hz?

 

I'm on PC and I'm aware that DisplayPort 1.4 already allows 4k @ 144hz with DSC or chroma subsampling -- which is specifically why I'm interested in whether the upcoming HDMI 2.1 monitors will offer 144hz without any form of compression. Otherwise, why upgrade to HDMI 2.1 at all?

 

Here's an article I found that says it can: https://www.cablematters.com/blog/HDMI/does-hdmi-support-144hz

 

But most other articles only list 4k 120hz for the HDMI 2.1 capabilities.

 

[Nathanpete]

I do not believe HDMI 2.1 has the bandwidth capable for full 4k144 without some sort of color or stream compression. Would be nice, but looks like it is DP 1.4 for us.

[mr fobs]

Because the HDMI 2.1 Specification is 4k@120Hz, I assume that they may have HDMI2.1 ports on them that only support 4K@120Hz, while the Display Port Port will support their full Resolution and refresh rate.

[Chris Pratt]

There's overhead in the signal for metadata, and of course bandwidth limits are always theoretical, and never actually that much in practice. Between the two 4K@120MHz is the best you can get.

 

However, that's just over HDMI. DP can go higher, and these new 4K displays will of course have DP as well. That's where you'll get 144Hz.

[Stahlmann]

Just use DP 1.4 with DSC as a PC monitor. It unlocks the full resolution and refresh rate and is visually lossless. Every comparison between DSC on and off had the same conclusion that it changed absolutely nothing in terms of image quality.

 

HDMI 2.1 is basically only important if you want to unlock 4K 120Hz modes on the newest consoles as the simply don't have a DP to use.

But there will be next to no game on these consoles that will use 4K AND 120Hz at the same time, so even there it's basically not really noteworthy...

[Stahlmann]

3 minutes ago, Chris Pratt said:

4K@120MHz is the best you can get.

120MHz seems a bit high for today's standards 

 

I know it was a typo

[Glenwing]

1 hour ago, Nathanpete said:

I do not believe HDMI 2.1 has the bandwidth capable for full 4k144 without some sort of color or stream compression. Would be nice, but looks like it is DP 1.4 for us.

 

46 minutes ago, Chris Pratt said:

There's overhead in the signal for metadata, and of course bandwidth limits are always theoretical, and never actually that much in practice. Between the two 4K@120MHz is the best you can get.

 

However, that's just over HDMI. DP can go higher, and these new 4K displays will of course have DP as well. That's where you'll get 144Hz.

No, HDMI 2.1 has enough speed for 4K 144 Hz uncompressed with 10 bpc color depth.

 

Bandwidth limits are exact for video interfaces, the link operates at a fixed frequency, there is an exact number of bits per second allocated for video, and video consumes an exact constant number of bits per second.

[p0tat0stix]

So to recap on the answers, which is why I asked the question in the first place:

 

No.

No.

Probably not.

Dont worry about it, use DisplayPort.

And a definite yes.

[Glenwing]

17 minutes ago, p0tat0stix said:

So to recap on the answers, which is why I asked the question in the first place:

 

No.

No.

Probably not.

Dont worry about it, use DisplayPort.

And a definite yes.

To clear things up, the short version is this: the highest Supported Format for 4K in the HDMI Specification is 120 Hz. People often misinterpret this to believe that HDMI 2.1 therefore doesn't allow higher than 120 Hz at 4K, because they don't understand what a Supported Format is in the context of the HDMI Specification. I explain in more detail here: https://www.reddit.com/r/Monitors/comments/eipp4h/why_doesnt_hdmi_21_support_refresh_rates_above/?utm_medium=android_app&utm_source=share

 

The exact same debate happened with HDMI 1.4, with people adamantly insisting that HDMI was not capable of 1080p 144 Hz, because "even though it has enough bandwidth, look the HDMI Specification only lists support for 1080p 120 Hz". But this was demonstrably wrong, and is just a misunderstanding of the HDMI Specification. HDMI is limited by bandwidth only; any arbitrary format is allowed as long as it falls within the bamdwisth limit. This is stated in the first sentence of the video section of the HDMI Specification.

[p0tat0stix]

22 minutes ago, Glenwing said:

To clear things up, the short version is this: the highest Supported Format for 4K in the HDMI Specification is 120 Hz. People often misinterpret this to believe that HDMI 2.1 therefore doesn't allow higher than 120 Hz at 4K, because they don't understand what a Supported Format is in the context of the HDMI Specification. I explain in more detail here: https://www.reddit.com/r/Monitors/comments/eipp4h/why_doesnt_hdmi_21_support_refresh_rates_above/?utm_medium=android_app&utm_source=share

 

The exact same debate happened with HDMI 1.4, with people adamantly insisting that HDMI was not capable of 1080p 144 Hz, because "even though it has enough bandwidth, look the HDMI Specification only lists support for 1080p 120 Hz". But this was demonstrably wrong, and is just a misunderstanding of the HDMI Specification. HDMI is limited by bandwidth only; any arbitrary format is allowed as long as it falls within the bamdwisth limit. This is stated in the first sentence of the video section of the HDMI Specification.

Glenwing, thank you for taking the time to explain this. Really appreciated!