Can HDMI 2.1 run 8K at 60Hz? Chroma subsampling and bandwidth requirements

How this is calculated

4:2:0 chroma subsampling halves the color-difference resolution, which is invisible for video content (movies, streaming) but slightly degrades fine-text edges on a desktop. That's an acceptable trade at 8K because the pixel density is already so extreme that the subsampling effect is below the threshold of perception at normal viewing distances. DSC is the alternative path, and it lets HDMI 2.1 carry 8K at 60 Hz with 10-bit 4:4:4 compressed to roughly 22.3 Gbps.

Verdict

8K at 60 Hz with 10-bit 4:2:0 chroma works out to 33.4 Gbps, the same number that 4K 120 Hz needs, which is the figure HDMI 2.1 was engineered around at the spec level. The trade for 4:2:0 is that color-difference resolution is halved, which is invisible at video viewing distance because 8K pixel density is so high that the subsampling effect is below perception, but slightly degrades desktop text edges. Doubling to 10-bit 4:4:4 takes the mode to 66.9 Gbps which exceeds the HDMI 2.1 ceiling, so DSC is the only path to full-chroma 8K 60 HDR, compressing to roughly 22.3 Gbps. That's the fork: video playback at 4:2:0 native, desktop and content-creation work with DSC and full chroma.