AMD Linux Drivers will now be supported by Dynamic VRS To Boost Steam Deck Power Efficiency. The latest graphics drivers for Linux are open-source which means not only AMD can contribute to it, but other parties too. One of the recent contributors to these drivers is Valve. Valve is in the process of shipping its handheld game console, Steam Deck, which highly relies on open-source drivers.
VRS(variable-rate shading) is a scheme that enables a game engine to spend less time on shading the pixels in regions that are off in the periphery or are poorly lit. This sort of shades pixel regions at lower and varying rates, and thus saves shader overhead to produce the final image. This scheme, if executed correctly, leaves a minimal impact on the graphics of the game, which is barely recognizable by the gamers and results in a performance boost too. The VRS was first implemented in a retail game in Wolfenstein II: The New Colossus, which uses the open-source Vulkan API.
While implementing VRS in Vulkan, VK_KHR_fragment_shading_rate extension is used for the control of shading rate in different areas of the frame. AMD has been supporting this extension in its RADV open-source Vulkan driver for Linux, but Valve has now been successful in implementing the ability to force per-vertex VRS with a certain shading rate dynamically. Michael Larabel, the founder of Phoronix, has claimed that this can let Valve define adjustable VRS rates according to the Steam Deck’s power state. Therefore, on disconnecting AC power, the Deck will slant the algorithm causing a slight decline in the visual quality to increase the battery life. It is actually very hard to imagine the Steam Deck getting a lot of mileage out of VRS because of the extremely low display resolution of 1280×800, but it should be kept in mind that it also features a very small GPU and a very tight power budget.