The 4k OLED TVs and LCD TVs with HDMI 2.1 connections that LG releases this year do not reach the maximum bandwidth of 48Gbit / s. The consequences seem limited, because this bandwidth is required for a 12-bit color depth and the TVs cannot process it.
LG has in a statement to Forbes let you know that the full bandwidth is only supported in two HDMI 2.1 connections on the 8k TVs that are yet to be released this year: the 8k TVs in the ZX series and the Nano 99, 97 95. The other HDMI 2.1 connections on these televisions and all HDMI 2.1 connectors on this year’s 4k TVs support lower bandwidth. LG does not say how high it is and apologizes for not communicating it before.
The manufacturer says that this means that the 2020 televisions with HDMI 2.1 connections are still able to display 4k images at 120fps, but this involves a 10bit color depth with 4: 4: 4 chroma subsampling. . Last year’s LG televisions, such as the C9 OLED TVs, do have HDMI 2.1 connections that achieve 48Gbit / s. They can therefore display 4k images at 120fps with a theoretical color depth of 12bit with 4: 4: 4 chroma subsampling.
LG explains that it has decided to do this on the basis of the market situation. According to the company, no ‘real content’ that requires 48Gbit / s is available yet. LG says it has allocated ‘hardware resources’ for the 2020 chipsets differently so that they are optimized for the ai features. In short, the manufacturer removes, as it were, part of the processing capacity of the processor from the HDMI 2.1 connections and makes it available for the various AI functions of the TVs.
For example, this year’s CX, WX, GX OLED TVs will have HDMI 2.1 connections, but will only reach 40Gbit / s. In practice, this will have little to no visible limitations, since none of the LG, Sony or Samsung TVs with HDMI 2.1 can handle a 12bit color depth. They are all 10bit systems.
John Archer, the author of the Forbes article, says Incidentally, it seems that almost no current television with HDMI 2.1 achieves the 48Gbit / s bandwidth and that none of them go beyond 40Gbit / s. This probably also applies to, for example, the Samsung TVs with HDMI 2.1 connections. According to Archer, only the Sony XH90-4k LCD TV has support for HDMI 2.1 with up to 48Gbit / s. Eric Beeckmans of Homecinema Magazine confirms that and states that the Sony ZH8 goes up to 40Gbit / s.