HDMI Licensing Administrator, the component designated by HDMI Forum that licenses, among other things, the HDMI 2.1 standard, states that HDMI 2.0 is no longer referenced and that it is now a sub-component of HDMI 2.1.
HDMI Licensing Administrator comes with this explanation based on questions asked by TFT Central. The monitor website did this partly in response to confusion about the specifications of a Xiaomi monitor. This is a 24.5″ display with 1080p resolution and a 240Hz refresh rate that has two HDMI 2.1 connections per stated specification. However, the two connections do not have capabilities beyond what the HDMI 2.0 standard entails, but still are referred to as HDMI 2.1 The fact that this monitor is in fact an HDMI 2.0 monitor is also apparent from a further specification from Xiaomi, which refers to the transition minimised differential signaling protocol, which is the protocol of HDMI 2.0, while HDMI 2.1 uses a different protocol, namely fixed rate link.
HDMI Licensing Administrator is coming to TFT Central with a statement. First of all, the body states that HDMI 2.0 no longer exists and that devices should no longer claim to contain HDMI 2.0, because that version is no longer referenced. According to the licensor, the features of HDMI 2.0 are now a sub-component of HDMI 2.1. In addition, it is underlined that all new capabilities and features associated with HDMI 2.1 are optional. Finally, HDMI Licensing Administrator states that if a manufacturer claims that a device supports HDMI 2.1, “to avoid confusion”, it must also be stated which specific functions are supported.
As the HDMI 2.0 certification has come to an end, this explanation from the HDMI Licensing Administrator could mean that all devices with HDMI 2.x connections should bear the HDMI 2.1 label, even if they could a bandwidth and features that basically mean HDMI 2.0 support. The conclusion that the designation HDMI 2.1 then becomes rather meaningless is a position with which HDMI Forum does not agree, according to TFT Forum.
It has been known for some time that HDMI 2.1 should be regarded more or less as a menu for manufacturers and not as a well-defined set of standard requirements that must always be present one by one. This means that functions such as variable refresh rate, auto low latency mode, 4k120, enhanced audio return channel and quick media switching are not automatically all present with an HDMI 2.1 designation.