HDMI 2.1b, following minor updates, has introduced new capabilities, including higher video resolutions and refresh rates. This specification supports 4K video at 120 Hz, 8K video at 60 Hz, and even 10K video, with some PC graphics cards potentially supporting even higher rates. The rapid refresh rates offered by HDMI 2.1b are particularly beneficial for gaming, enabling advanced features such as VRR (variable refresh rate) for smoother gameplay, as well as ALLM (auto low-latency mode) and QFT (quick frame transport) to minimize latency. Additionally, it supports all high-bitrate audio formats, including DTS Master Audio, DTS:X, Dolby TrueHD, and Dolby Atmos.
Other notable features of HDMI 2.1 include HDMI eARC, which allows lossless high-resolution audio transmission between eARC-supported devices, and dynamic HDR support. This dynamic HDR optimizes HDR content either scene-by-scene or frame-by-frame.
Certain considerations related to HDMI ports are important to keep in mind. Dolby Vision HDR has previously delivered dynamic HDR to compatible TVs over HDMI 2.0, as it embeds dynamic metadata directly in the video stream. Similarly, HDR10+ can achieve the same. HDMI eARC is also available over HDMI 2.0, as seen in newer TVs from brands such as TCL and Hisense, which offer two HDMI 2.1 inputs alongside a separate HDMI eARC port.
While HDMI 2.1 is backward-compatible with older HDMI versions, not all features are supported. Users may need to upgrade their HDMI cables to accommodate the higher bandwidth required, transitioning from high-definition cables to ultra-high-definition cables.
With the release of HDMI 2.1b, which supports 8K and even 10K video along with major high-resolution audio formats, consumers are well-covered for home theater use. As a result, there is no immediate need to upgrade to HDMI 2.2 for TV or audio devices.
The HDMI Forum, however, is promoting the new HDMI 2.2 specification for commercial applications and advanced consumer technology, such as augmented reality (AR) and virtual reality (VR) devices. HDMI 2.2 significantly enhances bandwidth transmission, doubling it from 48 Gbps to 96 Gbps, to better support demanding, data-intensive, and immersive applications, as stated by the Forum.