It depends upon the choice of your requirement or what you consider better. The HDMI 2.1 brings high resolutions and even high frame rates while HDMI 2.0b is a perfect vision for 4k resolution, but you can get the 4k at 120Hz and 8k at 60Hz is some clear facts for the users. You can get Monoprice 8K HDMI Cable (HDMI 2.1) for high-end results and maintains high resolutions.