The HDMI you think is not the HDMI you think

According to incomplete statistics, since 2003, when products with HDMI interface were officially put on the market, so far, more than 10 billion devices with HDMI interface have been sold worldwide, and the HDMI standard has evolved from version 1.0 to version 2.1.

The HDMI standard has changed recently, and this new change can be said to have brought a lot of trouble to ordinary users when purchasing products.

HDMI 2.0 "programming" is canceled

HDMI (High-Definition Multimedia Interface) is one of the most common electronic product interfaces, and can be seen everywhere in computers, monitors, TVs, set-top boxes, projectors and other products. The formulation and promotion of the HDMI standard is completed by the HDMI Forum and its authorized HDMI Licensing Administrator Inc. (HDMI LA). However, due to their management mistakes in the naming change of the standard version, it has caused confusion in the labeling of finished products on the market.

With an announcement from the HDMI Forum, the HDMI 2.0 standard will no longer exist - "programming" has been canceled, and only HDMI 1.4 and 2.1 will remain.

The original words from the HDMI Forum are: HDMI 2.0 no longer exists, and devices should not claim v2.0 compliance because it is no longer referenced; HDMI 2.0 features are now a subset of 2.1; all new functions and features related to HDMI 2.1 are all optional (including FRL, higher bandwidth, VRR, ALLM, and everything else); if a device claims to be 2.1 compliant, they also need to state what features the device supports to avoid "confusion".

From now on, what you think supports HDMI 2.1 may not be the HDMI 2.1 you think.

HDMI 2.1 standard features and detailed explanation

According to the official statement of the HDMI Forum when the HDMI 2.1 standard was announced, compared with the 2.0 standard that existed at that time, the features of the 2.1 standard include:

Supports higher resolutions and faster refresh rates (including 8K 60Hz and 4K 120Hz), up to 10K resolution, for commercial, industrial and professional use.

Dynamic HDR - Make every frame of your video show ideal values for depth of field, detail, brightness, contrast, and a wider color gamut.

The Super Speed -HDMI cable (compared to the previous high-speed HDMI cable) supports the 48Gbps bandwidth supported by the uncompressed HDMI 2.1 feature. The EMI emitted by the cable is extremely low.

eARC simplifies connections, makes it easier to use, and supports more audio formats and higher audio quality, while ensuring full compatibility between audio devices and HDMI 2.1 products.

Enhanced gaming features ensure smooth and seamless movement and transitions for games, movies and video footage, including:

Variable Refresh Rate (VRR) eliminates lag, stuttering and tearing for smoother, more detailed gameplay;

Auto Low Latency Mode (ALLM) automatically sets the ideal latency setting for smooth, lag-free and uninterrupted viewing and interaction; Quick Frame Transfer (QFT) reduces latency for lag-free and smoother gaming and interactive VR implementations .

Quick Media Switching (QMS) for movies and video eliminates delays that can cause black screens before displaying content.

HDMI Cable Power enables an active HDMI cable to be powered directly from the HDMI connector, eliminating the need to connect a separate power cord. This way, connecting and using an active HDMI cable is as easy as using a passive wired HDMI cable.

In the above part, the difference between the transmission bandwidth, resolution and refresh rate of HDMI 2.1 and 2.0 is not clearly explained.

The "perfect" HDMI 2.1 supports "FRL" (Fixed Rate Link) signals. FRL is a signaling technology supported in the HDMI 2.1 specification and is required to achieve higher uncompressed resolutions (such as 8K@60Hz and above) and ultra-high-speed bandwidths up to 48Gbps. It is also required for compressed video transmission, which in turn can operate at lower data rates (eg. 4K@60Hz).

However, in the HDMI 2.0 standard, the TMDS (Transmission Minimized Differential Signaling) signaling method is used, which can provide a maximum transmission bandwidth of 18Gbps on this interface. TMDS allows support for 4K@60Hz and 8-bit color depth, which is far from the 2.1 standard.

After the cancellation of the 2.0 standard, there will be products that still use TMDS signaling, but because they meet the requirements of the 2.1 standard in other features, they can be marked as HDMI 2.1.

In fact, there are already fast-moving manufacturers "responding" to the HDMI Forum's request to mark products that could only be marked as 2.0 as 2.1. A certain brand of display advertises the use of HDMI 2.1 interface, but the bandwidth actually only supports HDMI 2.0 bandwidth of 18Gbps. There is also a domestic speaker that uses 18Gbps bandwidth transmission and only supports the eARC function in 2.1, so it has been updated to HDMI 2.1 products.

Choose Notes

HDMI 2.1 requires the output device (such as PS5) and the output device (monitor, TV, speakers, etc.) to cooperate with each other. Therefore, you must first sort out your own needs, play games, watch movies, or enjoy music, and then check whether the characteristics of the product meet your requirements when choosing.

At the current stage, products still marked with HDMI 2.0 will also have some features up to the standard 2.1. For products marked with 2.1, please pay attention to whether there will be special instructions with asterisks on the product introduction page, indicating which features of the product meet the 2.1 standard and which do not meet the 2.1 standard.

Gamers have requirements for VRR variable refresh rate, and need to pay attention to whether the TV or monitor supports FreeSync or G-SYNC.

There is no distinction between 2.0 and 2.1 for HDMI cables. The HDMI Forum only gives the definition of high-speed cables and ultra-high-speed cables. In addition, the HDMI cable is only a physical transmission channel, and there is no dedicated chip, so the cable can be selected from a well-known brand. In the short distance (≤1.5 meters) of copper cables, there is little difference between high-speed lines and super-high-speed lines. For medium-distance (1.5-3 meters), choose super-high-speed lines, preferably with the official HDMI certification mark. For long-distance transmission requirements, the signal attenuation of copper cables is relatively obvious. It is best to choose HDMI 2.1 cables with optical fiber + copper cable structure. It is recommended to find official stores of well-known cable manufacturers for customization.

It is said that the HDMI Forum is preparing a new HDMI 2.1a standard, adding new features on the basis of 2.1, aiming to promote HDR content support, but as far as consumers are concerned, it is still hoped that the HDMI Forum will be able to clear the source as soon as possible in terms of standard version management.