DisplayPort 2.1b addresses cable length issues
A new version of the HDMI interface, HDMI 2.2 with new Ultra96-class cables was announced at CES. VESA’s competing DisplayPort standard is also getting an update, perhaps as a reaction to the new HDMI. It’s a minor upgrade though, with its label DisplayPort 2.1b indicating smaller changes compared to the previous new version 2.1a. This standard will be the first 2.x version available on Nvidia graphics cards.
The DisplayPort 2.1b specification is due to be released in the spring, so it’s still a preliminary announcement (but it’s the same with HDMI 2.2, which also doesn’t have a final specification out yet). The primary focus of this improved version is to make it easier to connect monitors with the highest speed, i.e. in DisplayPort 2.1 UHBR20 mode, which has a bandwidth of 77.37 Gbps (but the raw bitrate including overhead and metadata is 80 Gbps).
This speed is very demanding on the signal quality and passive cables commonly available on the market that handle this speed seem to be limited to 1.0–1.2 meters in length. This can easily become insufficient to bridge the distance between the PC’s graphics output and the monitor, if the PC case is not sitting right next to it on the desk (for the lower speeds of UHBR10 and UHBR13.5, longe cables are available, but not so for UHBR20).
DisplayPort 2.1b solves this by introducing new cables with the DP80LL designation, while the regular cables available until now for the UBHR20 mode come with the DP80 designation. The LL stands for Low Loss (i.e. low signal loss). These cables are supposed to be able to maintain a reliable connection between the video source and monitor for up to 3 meters while supporting UHBR20.
While the designation suggests that the improvement is achieved through choice of material, shielding or similar means, the DP80LL cables actually use an active principle, according to a press release from the VESA consortium, so they incorporate repeaters or other means of actively boosting or reconstructing the signal. However, this also means that they will be more expensive than regular DP80 cables.
DisplayPort 2.1b is already listed as being supported on GeForce RTX 5000 graphics cards, which were also revealed at CES 2025. VESA states that Nvidia has collaborated on the development of the specification and should ensure compatibility between these new cables and RTX 5000 generation graphics cards. While DisplayPort 2.0/2.1 as such was already supported by previous generations of Intel Arc and AMD Radeon graphics cards, Nvidia has so far been limited to the old DisplayPort 1.4a, which means the now upcoming Blackwell architecture graphics cards will be the first with the newer version.
Whether the DP80LL cables will work with other currently available graphics cards and whether DisplayPort 2.1b needs any specific hardware support, we don’t know. The press release doesn’t indicate whether all the magic happens just inside the cable without the graphics card or monitor needing to know about it (so that existing graphics cards that only support DP 2.1 or DP2.1a would work), or whether there is some power supply or signalling needed from the graphics card or from the output on a laptop, for example.
In any case, the new DP80LL active cables should be available on the market in the coming months.
Source: VESA/DisplayPort, VideoCardz, Club 3D (headline image)
English translation and edit by Jozef Dudáš
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