What is HDMI 2.1? Features and benefits explained

HDMI 2.1 is the newest version of HDMI technology. Certain features of HDMI 2.1 are already present on some TVs produced in 2019 and onwards (check the list here). 

Do I need HDMI 2.1?

HDMI 2.1 is Future-proof

From 2020 onwards, HDMI 2.1 features will begin to appear in more and more TVs and eventually become the new norm. If you wish to purchase a new TV consider one that supports HDMI 2.1 features to enhance your viewing experience on next-generation consoles and video devices.
 

What are HDMI 2.1 features?

Native 4K 120 FPS content viewing and fast response

4K resolution combined with 120 FPS at present provides the highest level of smoothness and clarity for video and game content. These capabilities coupled with next-generation games dramatically reduce input lag while significantly increasing response speed. This means that the delay between the screen and your commands will reduce, while the response time for pixels to change from one colour to the next also improves.

Variable Refresh Rate (VRR)

What is VRR
VRR refers to the way your TV adjusts its refresh rate to match the frame rate of the output device. Frame rates typically vary in real time and are influenced by the scene that is displayed on your TV. 

VRR also eliminates stutter delays and screen tearing to produce a smoother image. Gaming monitors also use this technology. By integrating VRR into HDMI 2.1, the differences between PC gaming and console gaming reduces. However, VRR specified by HDMI 2.1 is not compatible with AMD Free Sync which appears in PC gaming software.

VRR for gaming
Video games often incorporate dramatic scene changes from sudden explosions to swift colour changes, which cause the frame rate to reduce drastically. VRR compensates for these changes by simultaneously matching the refresh rate to the frame rate of the game. The result is a reduction in stutter delay and screen tearing which together creates a smoother image. VRR is extremely important for seamless gaming, unlike films where frame rates are relatively stable (usually 24FPS). 
 

Auto Low Latency Mode (ALLM, also known as Auto Game Mode)

ALLM detects when a console is turned on and automatically switches the TV to game mode. Game mode reduces the delay between your inputs on a controller and the corresponding action that takes place on your TV. 
 

Enhanced Audio Return Channel (eARC)

With an eARC channel, you can enjoy the depth of movie theatre quality surround sound via DOLBY ATMOS and DTS:X. Due to the limitations of regular ARC, only eARC is able to process these formats.
 

Chroma subsampling

4K 120 FPS 10 bit 4:4:4 will be included via a software update. A 4:4:4 ratio indicates that 8 out 8 pixels can display different colour information, as opposed to 4:2:2 (4/8 pixels) and 4:2:0 (2/8 pixels).