Mesa 21.x Seems To Muck Up Gamers' Trust Factor For Counter-Strike: Global Offensive
Those moving to Mesa 21.x releases for the latest open-source GPU driver support on Linux are seemingly finding their Valve "Trust Factor" matchmaking system scores dropping for Counter-Strike: GO, leading to numerous upset Linux gamers with AMD Radeon GPUs.
Back in January for Mesa 21.0 there was the CS:GO whitelisting for OpenGL threading with a focus on improving the performance for the RadeonSI Gallium3D driver with modern AMD Radeon graphics cards. Unfortunately, that appears to be lowering the Trust Factor for the game. Valve's Trust Factor is their matchmaking system in use for Counter-Strike: Global Offensive for finding gamers to compete against with similar scores. Cheating and other opaque inputs go in to calculating the Trust Factor value for a particular game.
While Mesa "glthread" is just about making use of threading for greater performance and is no way cheating, the Trust Factor handling in CS:GO seems to go berserk for yet to be explained reasons. Thus by simply upgrading to Mesa 21.0 or later, this is hurting Linux gamers running CS:GO with Radeon graphics.
Going back to the end of January has been this Valve bug report over "severe degradation of trust factor" with Counter-Strike: GO. Going back to that original bug report there was a belief it may be something to do with the AMD driver environment variables.
Other Linux gamers also chimed in seeing an unexplained drop in their Trust Factor too. There has been much discussion and various hypothesis of the cause and how Trust Factor may be calculating its scores.
Quietly today pushed to Mesa Git is disabling of mesa_glthread for Counter-Strike: Global Offensive.
Timothy Arceri, who works on Valve's Linux graphics driver team, noted in the commit: "Users have reported a rise in trust factor problems since using mesa builds containing 6f2017205e62 [the GL threading for CS:GO]. Until we confirm its not a problem disable glthread."
Given the issue has been appearing since January after mesa_glthread was flipped on, it's too bad they weren't yet able to figure out the issue with Trust Factor itself yet. But for now if you do enjoy Counter-Strike: Global Offensive for competitive play and are concerned about your Trust Factor and using Radeon graphics, look ahead to forthcoming point releases for this patch back-ported or just set mesa_glthread=false as an environment variable when firing up CS:GO to ensure the feature is disabled.