HDMI® Specification 2.1 supports end-to-end 8K/4K resolutions and higher refresh rate solutions with a single upgraded cable for seamless integration with the HDMI eco-system.
8K delivers a super-immersive viewing experience with 2x the horizontal and vertical resolution of 4K, and 4 times as many pixels; and combined with 60Hz refresh rate enables smooth and sharp viewing of content with high-speed action. 4K@120Hz enables ultra-fast motion UHD images to be crisp and razor sharp; and sports, action movies, high-performance gaming and VR benefit significantly.

HDMI 2.1 High Video Resolutions and Signaling Technology

Q：Will 8K@60 or 4K@120 require a new cable?
A:Yes, in order to ensure performance and compatibility the Ultra High Speed HDMI Cable is required.
Q：What are the supported resolutions and frame rates?
A:
4K50/60
4K100/120
5K50/60
5K100/120
8K50/60
8K100/120
10K50/60
10K100/120

Q:Is compression used to achieve those resolutions and frame rates?
A:The specification supports both uncompressed and compressed modes. Manufacturers can implement either or both modes. The designations are:
4K100A    - supports uncompressed mode
4K100B    - supports compressed mode
4K100AB   - supports both
4K120A    - supports uncompressed mode
4K120B    - supports compressed mode
4K120AB   - supports both
8K50A      - supports uncompressed mode
8K50B      - supports compressed mode
8K50AB    - supports both
8K60A      - supports uncompressed mode
8K60B      - supports compressed mode

Q:How do I identify which compression modes are supported in my products?
A:Manufacturers may use the designations indicated above (e.g. 8K60A, 8K60B, 8K60AB) in their product marketing, advertising, user guides, packaging, website, and on-product.

Q:What type of compression is supported?
A:The specification incorporates VESA DSC 1.2a link compression, which is a visually lossless compression scheme. VESA DSC 1.2a also can be used to obtain higher resolutions than 8K60/4:2:0/10-bit color, such as 8K60 RGB, 8K120 and even 10K120. VESA DSC 1.2a also supports 4Kp50/60 with the benefit of enabling operation at much lower link rates.

Q:What colorimetry is supported?
A:HDMI 2.1 Specification supports the latest color spaces including BT.2020 with 10, 12, and 16 bits per color component.

Q:What is FRL and is it necessary for the higher resolutions and faster refresh rates?
A:FRL stands for Fixed Rate Link and it’s a signaling technology supported in the HDMI 2.1 Specification. FRL is necessary to achieve the higher uncompressed resolutions such as those above 4k60 as well as the ultra high speed bandwidths up to 48Gbps. It’s also required for compressed video transport which in turn enables operation at lower data rates for example 4k60 and ultra-high pixel rate video such as 10Kp120.

Q:Does FRL replace TMDS?
A:Yes, it replaces TMDS. Note that the HDMI 2.1 specification still requires support for TMDS for backwards compatibility and still seamlessly supports the billions of HDMI devices that utilize TMDS.

Q:Can FRL be implemented through a firmware upgrade?
A:Upgradeability needs to be designed into the silicon and that is up to the manufacturers, although implementing FRL is most likely going to require new hardware.