SteamOS 3.8.20 Beta released with VRAM handling update
The key change is listed by Valve as “greatly improved VRAM management,” with the goal of improving performance and stability when VRAM is under pressure. Valve does not mention a specific patch series in the public changelog, but the wording matches recent Linux graphics work focused on keeping foreground games from being pushed out of dedicated video memory.
This type of change is more relevant for systems with dedicated GPUs and limited VRAM. On those systems, Linux can move GPU allocations to system memory through GTT when VRAM fills up. That can cause stutter or lower performance because system memory is much slower than local VRAM.
Source: Valve
Valve engineer detailed a related dmem cgroup-based approach in April . The work uses kernel patches and user-space tools such as dmemcg-booster and plasma-foreground-booster to prioritize foreground applications. Vock noted that iGPU and APU systems may see a smaller effect because they already use system memory for graphics.
Mesa graphics driver update
SteamOS 3.8.20 Beta also updates Mesa to a new major release. Valve says the new driver contains many ray tracing performance improvements, along with other performance and functionality changes. The public changelog does not list the exact Mesa package version.
This beta alsoincludes fixes that were also released to the stable channel as SteamOS 3.8.12. Those include a Steam streaming fix for fullscreen games in Desktop Mode, a graphics driver fix for the Sniper Elite 5 main menu, and SD card reader fixes for some Lenovo Legion Go S models.
The update is still limited to the Beta and Preview channels. Users can enable it from Settings, System, System Update Channel.
Source: Valve Steam
