For Linux users, Intel is working on implementing Display-Port Multi-Stream Transport with Display Stream Compression for the very first time in Linux with its Arc GPUs, as reported by Phoronix. This feature will allow users the ability to daisy chain three 4k 60Hz monitors together with DisplayPort 1.4 on Arc graphics, instead of just two. This feature is expected to come soon, and could arrive as early as October with Linux kernel 6.1 if development go smoothly.
For reference, this is a Linux-specific update. We aren't sure whether or not Windows Arc GPU drivers already support DP MST with DSC or not — at least for triple display outputs.
According to Phoronix, this is the first time we've seen this feature implemented on Intel graphics at all. Intel's Linux drivers to date have only supported Display Stream Compression without daisy chaining (MST), including Intel's integrated graphics solutions.
For now, it appears that Intel will only be pushing out this feature to its open-source driver stack for Arc GPUs. Integrated graphics support remains a mystery at this point, which is a shame, since integrated graphics powered notebooks would benefit a lot from this feature.
Nonetheless, we will be seeing discrete Arc GPUs in desktops and laptops getting this feature soon in Linux. It's probably not a very useful feature on desktops, due to current AIB partner card Arc Alchemist GPUs featuring four display outputs. But for Arc-powered laptops, with much more limited display output connectivity, this feature could be very useful for power users running Linux.
Phoronix says this feature is just one of many improvements coming to Intel's open-source discrete GPU driver stack in the upcoming months. Current Intel drivers supporting Arc are still in the experimental stage and require bleeding edge Mesa versions and Linux distros to work.
However Intel has been hard at working bringing a number of improvements to Linux kernel 6.1, which could bring the driver out of the experimental stage, and into a more stable package that more people can use on different Linux versions.
DP MST with DSC in particular could arrive as early as October, with the introduction of Linux 6.1 kernel cycle as well, but only time will tell if this feature arrives in October or gets delayed to a later kernel update.
Usually Intel is the most compatible and offers the most resolution options. At least HDMI 2.0 universally works on my 2014 4k.
Hopefully their dgpu drivers are better.