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Drivers & Software

Adept II

RX6900XT HDMI 2.1 issues.

I have 2 major problems with a newly purchased RX6900XT GPU that never occurred on GTX 1070Ti and RTX 3080 I was using.

This is connected to a LG OLED C9 TV.

First issue:

The GPU is limited to 4k/120hz 10bit 4:4:4 RGB or 4k/60hz 12bit 4:4:4 RGB in windows but not 4k/120hz 12bit 4:4:4 RGB.

RTX 3080 is outputting 4k/120hz 12bit 4:4:4 RGB just fine.

This seems to be a 40Gbps cap on AMD's HDMI 2.1 implementation that was never mentioned and I have no idea whether this is a hardware limitation or it can be fixed with a driver update to give us full 48Gbps HDMI 2.1 bandwidth as it supposed to be,

Second issue:

4K HDR videos do not run in 12bit or 10bit YCbCr 4:2:2 format and the only option is 10bit YCbCr 4:2:0 and that is not good.

Again, both GTX 1070Ti and RTX 3080 support 12bit YCbCr 4:2:2 just fine.

I need to know whether these 2 issues can be fixed or not before losing the ability to return my RX6900XT.


1 Reply
Adept II

Third issue discovered today:

Any refresh rate less than 100hz will result in losing HD audio from movies via every media player I tried.

So basically, I can't run movies in 24p in their native framerate with HD audio AT ALL!.