Challenges Faced by AMD in Implementing HDMI 2.1 Alex Deucher, an AMD developer, has been working for over two years to achieve HDMI 2.1 support. Despite creating an open-source Radeon driver that includes HDMI 2.1 support and extensive legal discussions with AMD since February 2023, the HDMI Forum's recent rejection has thwarted these efforts for AMD and Linux enthusiasts. HDMI Forum Denies Open Source HDMI 2.1 Proposal The HDMI Forum's decision to decline the open source HDMI 2.1 proposal complies with its guidelines, making an open source version of HDMI 2.1 impossible.
Linux Users Must Depend on DisplayPort Without HDMI 2.1 support, Linux users in need of high-resolution and high-refresh-rate displays must rely on DisplayPort alternatives in open source, as AMD's Radeon drivers will initially only support HDMI 2.0. Nvidia, Intel, and Apple's Different Strategies Nvidia has taken a proprietary approach to enable HDMI 2.1 on Linux, moving essential features to the closed-source part of their drivers. Conversely, Intel and Apple use internal DisplayPort to HDMI converters in their chips to provide HDMI 2.1 functionality on Linux while maintaining DisplayPort compatibility.
Source: Alex Deucher