Steam Machine may support 4K and 120 Hz with HDR and VRR after all

HDMI 2.1 with AMD graphics chips and Linux was previously not possible. As we reported in December the HDMI Forum's license terms require that a non-disclosure agreement be signed in order to gain access to all HDMI 2.1 features. However, this is not compatible with an open source operating system such as SteamOS, whose source code is published in its entirety. AMD may now have found a solution to this problem.

As Phoronix reports, AMD has released a series of Linux kernel patches that introduce support for HDMI Fixed Rate Link (FRL), a feature exclusively supported by HDMI 2.1. This allows the available bandwidth to be increased up to 48 Gbps, enabling 4K monitors to run at up to 120 Hz without the need for additional compression, which would negatively impact image quality. An AMD developer has stated in the Phoronix Forum that a full HDMI 2.1 implementation for Linux-based operating systems will be available sooner or later, once the necessary compliance testing has been completed.

Once ready, the Steam Machine will be able to support a number of additional features, including HDMI Variable Refresh Rate to automatically adjust the frame rate of a monitor or smart TV to match the actual frame rate of the game. The HDMI Auto Low Latency Mode (ALLM) can reduce input latency. The Steam Machine is currently still being advertised with HDMI 2.0 and only supports 4K at 120 Hz with a reduced color spectrum.

Even if this does not change before the launch, Valve could subsequently upgrade the HDMI standard to HDMI 2.1 via a firmware update, provided the hardware supports the newer standard. Since even the Nintendo Switch 2 ($449 on Amazon) supports HDMI 2.1, hardware support should not be the biggest obstacle for Valve.