IT Times reporter ■ Lin Fei
According to incomplete statistics, since the products using HDMI interfaces were officially put on sale in 2003, more than 10 billion devices with HDMI interfaces have been sold worldwide, and the HDMI standard has evolved from version 1.0 to version 2.1.
The standard of HDMI has recently changed, and this new change can be said to have brought a lot of trouble to ordinary users when buying products.
HDMI 2.0 "orchestration" was canceled
HDMI (High-Definition Multimedia Interface) is one of the most common electronic product interfaces, which can be found everywhere in computers, monitors, televisions, set-top boxes, projectors and other products. The development and promotion of the HDMI standard was done by the HDMI Forum and its authorized HDMI Licensing Administrator Inc. (HDMI LA), but due to their management errors in the naming of the standard version, the current situation of marking the finished product on the market is chaotic.
With an announcement from the HDMI Forum, the HDMI 2.0 standard will no longer exist – the "compilation" will be abolished, and the HDMI standard will only be 1.4 and 2.1.
The original words of the HDMI forum were: HDMI 2.0 no longer exists, devices should not claim to be compliant with v2.0 because it is no longer referenced; the features of HDMI 2.0 are now a subset of 2.1; all new features and features related to HDMI 2.1 are optional (including FRL, higher bandwidth, VRR, ALLM, and everything else); if devices claim to be compliant with 2.1, then they also need to indicate which features the device supports so as not to "confuse".
From now on, what you think of as a product that supports HDMI 2.1 may not be the HDMI 2.1 you think.
HDMI 2.1 standard features and details
According to the official statement of the HDMI Forum when the HDMI 2.1 standard was announced, compared with the 2.0 standard that still 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) and can support up to 10K resolution for commercial, industrial and professional use.
Dynamic HDR – Allows every frame of video to show ideal values for depth of field, detail, brightness, contrast, and a wider color gamut.
Ultra-high-speed HDMI cables (compared to previous high-speed HDMI cables) support the uncompressed HDMI 2.1 feature supported 48Gbps bandwidth. The EMI emitted by the cable is extremely low.
eARC simplifies connectivity, is 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 transition of gameplay, movies, and video footage, including:
Variable Refresh Rate (VRR) eliminates lag, stuttering, and torn graphics for a smoother, more realistic gaming experience;
Automatic Low Latency Mode (ALLM) automatically sets the ideal latency setting for smooth, hysteresis-free, and uninterrupted viewing and interaction, while Fast Frame Transfer (QFT) reduces latency and makes gaming and interactive VR implementations lag-free and smoother.
Fast Media Switching (QMS) for movies and videos eliminates delays that can lead to black screens before the content is displayed.
The HDMI cable power supply allows the active HDMI cable to be powered directly by the HDMI connector without the need to connect a separate power cable. This makes connecting and using an active HDMI cable as simple as using a passive wired HDMI cable.
In the above part, in fact, the difference between the transmission bandwidth, resolution, and refresh rate of HDMI 2.1 and 2.0 is not clear.
"Perfect" HDMI 2.1 supports "FRL" (Fixed Rate Link) signals. FRL is a signaling technique supported in the HDMI 2.1 specification and is necessary to achieve higher uncompressed resolutions (e.g., 8K 60Hz and above) and ultra-high-speed bandwidths up to 48Gbps. It is also needed for compressed video transmission, which in turn can operate at lower data rates such as 4K 60Hz.
However, in the HDMI 2.0 standard, the TMDS (Transmission Minimized Differential Signaling) signaling method is used, which provides a maximum transmission bandwidth of 18 Gbps on this interface. TMDS allows support for 4K 60Hz and 8-bit color depth, which is a big gap from the 2.1 standard.
After the cancellation of the 2.0 standard, there will be products that can be labeled as HDMI 2.1 even if they still use TMDS signaling, but because they meet the requirements of the 2.1 standard in other features.
In fact, there are already fast-moving manufacturers who have "responded" to the request of the HDMI forum to label the products that could only be labeled as 2.0 as 2.1. A brand of monitors 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, using 18Gbps bandwidth transmission, only supports the eARC function in 2.1, and is updated to HDMI 2.1 product.
Selection considerations
HDMI 2.1 works properly and requires output devices (e.g. PS5) and output devices (monitors, TVs, speakers, etc.) to work with each other. So first sort out your own needs, play games, watch movies, or enjoy music, and then choose to see if the characteristics of the product meet your requirements.
At this stage, products that are still marked with HDMI 2.0 will also have some features that meet the standard of 2.1. For products marked 2.1, please pay attention to whether there will be a special description of the asterisk 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 rates 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, and the HDMI forum only gives the definition of high-speed lines and ultra-high-speed lines. In addition, the HDMI cable is only a physical transmission channel, and there is no exclusive chip, so the wire can choose a well-known brand. The short distance (≤1.5 meters) of the copper cable cable is not much different from the ultra-high-speed line, and the medium distance (1.5 meters-3 meters) chooses the ultra-high-speed line, and it is best to have the official certification mark of HDMI. And then long-distance transmission needs, copper cable signal attenuation is more obvious, it is best to choose fiber + copper structure of HDMI 2.1 cable, it is recommended to find a well-known wire manufacturers official store customization.
For PS5 players, if you don't want to bother, directly in the Sony TV to pick the "Perfect for PlayStation 5" labeled model, look at the literal meaning to know that these products Sony officially optimized for the PS5, such as A90J, X90J, X95J. It should be noted that sony part of the "Ready for PS5" is still on sale on the older model, does not support variable refresh rate (VRR) and automatic low latency mode (ALLM), PS5 gaming experience is slightly worse.
Judging from the feedback from players, some features are currently only used exclusively by Sony. For example, HDR Auto HDR Tone Mapping - PS5 will automatically match the most ideal HDR settings after identifying the TV model.
It is said that the HDMI forum is preparing a new HDMI 2.1a standard, adding new features on the basis of 2.1 to promote HDR content support, but as far as consumers are concerned, they still hope that the HDMI forum can get the original in terms of standard version management as soon as possible.