Almost everyone in the HD era knows HDMI, because this is the most mainstream HD video transmission interface, and the latest 2.1A specification can even support 8K Ultra HD video specifications. The main material of the traditional HDMI line is mostly copper, but the copper core HDMI line has a disadvantage, because the copper wire resistance has a large attenuation of the signal, and the stability of the high-speed signal transmission will also have a greater impact on long-distance transmission.
Taking the current commonly used HDMI2.0 and HDMI2.1 as an example, HDMI2.0 can support up to 4K 60Hz video output, but HDMI2.0 does not support turning on HDR in the case of 4K 60Hz color space is RGB, and only supports turning on HDR in THE COLOR MODE OF YUV 4:2:2. This means sacrificing a certain amount of color surfaces in exchange for a higher refresh rate. And HDMI 2.0 does not support the transmission of 8K video.
HDMI2.1 can support not only 4K 120Hz, but also 8K 60Hz. HDMI2.1 also supports VRR (Variable Refresh Rate). Gamers should be aware that when the screen refresh rate of the graphics card output and the refresh rate of the monitor do not match, it may cause the picture to tear. The easiest way to do this is to turn on VSY, but turning on VS will lock the number of frames at 60FPS, affecting the game experience.
To this end, NVIDIA introduced G-SYNC technology, which coordinates the data synchronization between the display and the GPU output through the chip, so that the refresh delay of the display is exactly the same as the GPU frame output delay. Similarly, AMD's freesync technology. VRR (variable refresh rate) can be understood as the same as G-SYNC technology and freesync technology, which is used to prevent the high-speed moving screen from tearing or stuttering effect, ensuring that the game screen is smoother and more complete in detail.
At the same time, HDMI2.1 also brings ALLM (Automatic Low Latency Mode). Users of smart TVs in automatic low-latency mode do not manually switch to low-latency mode based on what the TV plays, but automatically enable or disable low-latency mode based on what the TV plays. In addition, HDMI2.1 also supports dynamic HDR, while HDMI2.0 only supports static HDR.
The superposition of so many new technologies, the result is the explosion of transmission data, in general, the "transmission bandwidth" of HDMI 2.0 is 18Gbps, which can transmit 3840 * 2160@60Hz (support viewing 4K); to HDMI 2.1, the transmission bandwidth needs to be 48Gbps, which can transmit 7680 * 4320@60Hz. HDMI cables also have indispensable characteristics as a link between devices and display terminals. The need for high bandwidth makes HDMI fiber optic cables born, here we will compare the similarities and differences between ordinary HDMI lines and optical FIBER HDMI lines:
(1) The core is not the same
The optical fiber HDMI cable uses optical fiber core, and the material is generally glass fiber and plastic fiber. Compared with the two materials, the loss of glass fiber is smaller, but the cost of plastic fiber is lower. In order to ensure performance, it is generally recommended to use plastic optical fiber for distances below 50 meters and glass optical fiber for more than 50 meters. The ordinary HDMI wire is made of copper core wire, of course, there are upgraded versions such as silver plated copper and sterling silver wire. The difference in material determines the huge difference between optical fiber HDMI cable and conventional HDMI cable in their respective fields. For example, optical fiber cables will be very thin, light and soft; while conventional copper core wires will be very thick, heavy, hard and so on.
2) The principle is different
The optical fiber HDMI line adopts the photoelectric conversion chip engine, which needs to be transmitted by two photoelectric conversions: one is the electrical signal into an optical signal, and then the optical signal is transmitted in the optical fiber line, and then the optical signal is converted into an electrical signal, so as to realize the effective transmission of the signal from the SOURCE end to the DISPLAY end. Conventional HDMI lines use electrical signal transmission and do not need to pass through two photoelectric conversions.
(3) The transmission validity is different
As mentioned above, the chip scheme used by optical fiber HDMI lines and conventional HDMI lines is different, so there are also differences in transmission performance. Generally speaking, because the photoelectric needs to be converted twice, the difference in transmission time between the optical fiber HDMI line and the conventional HDMI line on the short line within 10 meters is not large, so it is difficult to have an absolute victory or defeat in the performance of the two on the short line. Fiber optic HDMI lines can support lossless transmission of signals over 150 meters without the need for a signal amplifier. At the same time, due to the use of optical fiber as a transmission carrier, the high-fidelity effect of the signal is better and better, and it will not be affected by the electromagnetic radiation of the external environment, which is very suitable for games and high-demand industries.
(4) The price difference is large
At present, due to the optical fiber HDMI line as a new thing, the industry scale and user group are relatively small. So on the whole, the scale of optical fiber HDMI lines is small, so the price is still at a high level, generally several times more expensive than copper core HDMI lines. Therefore, the current conventional copper core HDMI line is still irreplaceable in terms of cost performance.
Post time: Apr-07-2022