AMD Fixes Linux HDMI 2.1 DSC Limitation; 4K 240Hz Steam Machines Within Reach

A well-known gap in AMD's GPU drive support on Linux was the absence of HDMI 2.1 and Display Stream Compression (DSC), but fortunately AMD open source software engineer Harry Wentland and the team have finally remedied the situation. Per an email publicly released on Freedesktop.org, AMD's Linux  display drivers have finally added support for these features and "passed a representative subset of HDMI compliance" with a full compliance run "in the works."

The lack of support is why the Steam Machine was announced with HDMI 2.0 support rather than HDMI 2.1, and the patch should allow the Steam Machine to run at up to 4K 240 Hz or 8K 120 Hz, though of course the limited power of the machine means it's still best-suited for 1080p gaming. High resolutions should benefit from the addition of DSC, though, since it will allow for full 10-bit color in line with the HDMI 2.1 specification.


AMD GPUs have typically been preferred on Linux machines due to how well AMD supports the open source drivers, and now one of the major downsides for owners of high-resolution, high-refresh rate displays has effectively been mitigated. Being limited to 60 Hz at 4K or 120 Hz with compressed 8-bit colors (aka chroma subsampling) was a considerable downside for users constrained by HDMI 2.0 on Linux, with text rendering being noticeably affected. It was far less noticeable in games or video playback, though, which is likely why Valve still supports 4K 120 Hz over HDMI 2.0 on the Steam Machine.

Hopefully by the time the Steam Machine actually launches, this patch will be pre-applied or ready to install. Kudos to AMD's Harry Wentland (as well as Jerry Zuo and Rodrigo Siquiera) for getting these issues sorted out with the driver ahead of launch.