[GTALUG] Intel GPU support for HDMI 2.0 (UltraHD)

[Lennart Sorensen]

On Mon, Feb 10, 2020 at 11:50:32AM -0500, Nicholas Krause via talk wrote:
> If I recall HDMI 2.0 like USB 3.2 and PCI 4.0 does not require a hardware
> upgrade. The protocol changed but older hardware should use it depending
> on if it can handle the new requirements. This was one of the reasons
> AMD did allow for awhile, PCI 4.0 on older Ryzen chipsets.
> 
> If HDMI for the last two versions is like this it really doesn't make sense
> to not allow it on certain older computers. Probably just a way for Intel
> to sell more chips maybe.
> 
> I could be mistaken but from memory this is what I recall,
> Nick

HDMI 1.0 through 1.2 had 4.95Gbps bandwidth (like DVI).  HDMI 1.3 and
1.4 had 10.2Gbps bandwidth.  HDMI 2.0 had 18Gbps bandwidth.  HDMI 2.1
has 48Gbps bandwidth.

So hardware changes are required to increase those link speeds.

Now 2.0a and 2.0b are just small additions to the protocol of 2.0.

The reason people want HDMI 2.0 and 2.1 is to get 4K resolution at a
decent frame rate, which HDMI 1.4 ports (like what intel still puts in
their graphics core) can't do.  30Hz doesn't cut it.

2.0 can do 4K 60Hz, but if you want HDR (so more than 24bit color) you
have to use chroma sub sampling and then text can start to look bad.
2.1 can do 120Hz and has the bandwidth for HDR as well.

-- 
Len Sorensen