The 4K OLED TVs and LCD TVs with HDMI 2.1 connections that LG is releasing this year do not reach the maximum bandwidth of 48Gbit/s. The consequences seem limited, because this bandwidth is needed for a 12-bit color depth and the TVs can’t handle it anyway.
LG has informed Forbes in a statement that full bandwidth is only supported in two HDMI 2.1 connections on the 8k televisions that are yet to be released this year: the 8k televisions in the ZX series and the Nano 99, 97 95 The other HDMI 2.1 connections on these televisions and all HDMI 2.1 connections on this year’s 4k TVs support a lower bandwidth. LG does not say how high it is and apologizes for not communicating this earlier.
The manufacturer states that this means that the 2020 TVs with HDMI 2.1 connections are still able to display 4k images with 120fps, but there is 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 reach 48Gbit/s. They can therefore display 4k images at 120fps with a theoretical color depth of 12bit with 4:4:4 chroma subsampling.
In explanation, LG says that it has decided to do so based on the market situation. According to the company, there is not yet any ‘real content’ available that requires 48Gbit/s. LG says it has re-allocated “hardware resources” for the 2020 chipsets 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.
This year’s CX, WX, GX OLED TVs, for example, will have HDMI 2.1 connections, but will achieve a maximum of 40Gbit/s. In practice, this will entail little to no visible limitations, as none of the LG, Sony or Samsung TVs with HDMI 2.1 can handle a 12-bit 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, Samsung TVs that are equipped 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 from Home Cinema Magazine confirms that and states that the Sony ZH8 goes up to 40Gbit/s.