HDMI 2.1 4K 120Hz vs 8K 60Hz

[leclod]

I just stumbled upon this, HDMI 2.1 is compatible with 4K 120Hz or 8K 60Hz as was HDMI 2.0 compatible with FullHD 120Hz or 4K 60Hz.

But 8K is 4 times the data of 4K while only half the refresh rate, no ?

So it seems HDMI 2.1 8K carries twice the data over HDMI 2.1 4K as did HDMI 2.0 4K over HDMI 2.0 FullHD

[Chris Pratt]

I could be wrong, but I think 8K@60Hz requires chroma subsampling, which accounts for the seeming bandwidth discrepancy. That, and I think HDMI 2.1 is actually capable of 4K@144Hz, it's just 120Hz is the more common refresh, especially for TVs where HDMI matters more. For monitors, you're still more likely to use DP.

[Glenwing]

9 hours ago, leclod said:

HDMI 2.0 compatible with FullHD 120Hz or 4K 60Hz.

HDMI 2.0 can transmit up to 240 Hz at 1080p or 60 Hz at 4K with 8 bpc RGB color. It isn't limited to 120 Hz.

9 hours ago, leclod said:

I just stumbled upon this, HDMI 2.1 is compatible with 4K 120Hz or 8K 60Hz as was HDMI 2.0 compatible with FullHD 120Hz or 4K 60Hz.

But 8K is 4 times the data of 4K while only half the refresh rate, no ?

So it seems HDMI 2.1 8K carries twice the data over HDMI 2.1 4K as did HDMI 2.0 4K over HDMI 2.0 FullHD

HDMI 2.1 does not support 8K 60 Hz with standard 8 bpc RGB color. It is only supported by using YCbCr 4:2:2 chroma subsampling, which reduces the data rate to 2/3, or DSC.

 

The limits of HDMI are detailed on the Wikipedia page.

https://en.wikipedia.org/wiki/HDMI#Refresh_frequency_limits_for_standard_video