HDMI cable
Source: Pascal Volk | Cropped & Resized | CC BY-SA 2.0

The specification for HDMI 2.1 has been announced officially, and we now have a clearer idea of its features. The new cables roll out next year and will bring up to 10K content with HDR and refresh rates of up to 120Hz.

In comparison, HDMI 2.0b supports 4K at 60 frames per second and a refresh rate of 60Hz. The refresh rate controls how often the display changes the image on the screen, with some monitors and TV’s supporting upwards of 144Hz.

For gamers, it means a smoother gaming experience when reaching framerates higher than 60. However, to reach that fps at 4K, gamers would need immense hardware, making this more of an investment in the future.

More useful today is HDMI 2.1’s support of variable refresh rates. With regular monitors, framerate and display refresh rate tends to sync up in pairs of 30. It’s why you hear targets of 30 and 60fps so often – going between those numbers can cause visual artifacts known as screen tears.

Technology from AMD and Nvidia changes that by allowing a variable refresh rate, but HDMI hasn’t traditionally supported it. This has led most to use DisplayPort cables, which support FreeSync and GSync technologies. With its improvements in various areas, 2.1 will be a much more usable solution for gamers.

Dynamic HDR

However, HDMI 2.1 also has some improvements for the regular TV user. Most movies are shot at 24 fps, making refresh rates pretty much irrelevant. HDR, on the other hand, can make a huge difference to viewing, increasing the range of colors and creating better contrast.

HDMI has supported regular HDR since 2.0a in 2015, but 2.1 introduces dynamic HDR capabilities. Rather than a blanket application, it can alter the brightness of individual frames and scenes throughout a movie to match the director’s intention.

As well as video, the new specification improves the audio side of things. Support for eARC means higher bitrate audio, as well as Dolby TrueHD, Dolby Atmos, DTS Master and more.

It joins features like Quick Media Switiching, Quick Frame Transport, Auto Low Latency Mode and more for a much future-proof experience. Microsoft’s Xbox One X is the only console to support HDMI 2.1, and should have access to many of these features.

You can view the full list of features via the official press release.