The Xbox One X is the first device to support HDMI 2.1
HDMI 2.1 is still in its infancy with no new devices certified yet as being fully compliant but apparently the Xbox One X is inherently capable of delivering some of the HDMI 2.1 goodies such as Variable Refresh Rate (VRR) and Auto Low Latency Mode (ALLM) as was demonstrated during Computex 2018. These features will be enabled via a firmware update to the Xbox One X and will work with compatible TV sets. The best part is that the console itself does not require a re-certification for enabling these features.
While the HDMI 2.1 spec supports a lot more features such as support for up to 10K resolution, [email protected]/[email protected], Quick Frame Transport, Quick Media Switching etc, the Xbox One X will be getting the two most important features that would interest gamers viz. the Variable Refresh Rate (VRR) made possible via AMD Freesync 2 and Auto Low Latency Mode (ALLM). VRR will match the refresh rate of the display with the console to prevent screen tearing and deliver smooth visuals. ALLM checks the TV for a suitable game mode setting and automatically switches to that to prevent lag while applying image processing. Additionally, the Microsoft rep in the video says that the console is capable of [email protected] and Dynamic HDR in the near future as it already has the required silicon. A firmware update will be released as and when such content is available.
There are a few things to be noted from this demonstration. Firstly, existing 18 Gbps HDMI 2.0 devices can be made HDMI 2.1 'capable' if they support one or more HDMI 2.1 specs. There are currently no 100% HDMI 2.1 certified devices in the market as the full 2.1 test spec itself is not available but that should change in 2019. Microsoft's ex-Head of Marketing for Xbox, Albert Penello, also recently tweeted that the Xbox One X need not undergo a full re-certification as long as the hardware supports one or more HDMI 2.1 features. Secondly, you need a compatible TV to realize these features as the hardware 'talks' to the TV to identify which features need to be turned on. While the chances of older TVs getting firmware updates are slim, newer models designed with the HDMI 2.1 spec in mind should be capable of supporting at least some of the features of the new spec.