A set of 14 patches were merged today to the Mesa 3D graphics driver codebase for fixing some wide-reaching performance issues that would have negatively affected the upcoming Xe3 integrated graphics with Core Ultra Series 3 “Panther Lake” hardware. The patches have been merged so will be very important that anyone buying an upcoming Intel Panther Lake laptop move to using an up-to-date Mesa to avoid these performance problems.
Intel engineer Francisco Jerez began the recent merge request with:
“This series addresses a number of compiler-related performance problems that would have affected xe3 platforms and led to less than ideal performance in most GPU workloads.”
Ouch, but at least caught ahead of product launch. The patches are focused on scheduling and thread parallelism optimizations for Xe3 and newer Intel graphics hardware. A lot of graphics compiler optimization work to avoid these performance pitfalls otherwise on Xe3.
Jerez encountered up to 18% better performance on a Panther Lake test system with these patches while for many game traces was in the 4~9% range. These performance optimizations though do come with a caveat of increased shader compilation time:
“The biggest downside is that the compile-time cost of this series is substantial in the ball-park of 25% for shader-db, but most of the compile-time impact is concentrated in the last patch that re-enables the static analysis-based SIMD32 heuristic on xe3 — Overall this gives back most of the gain in compile-time we had made by switching the SIMD32 heuristic while enabling VRT on xe3. However when combined with the performance analysis extensions to make it model the behavior of xe3 that last patch gives the largest performance benefit in the series, so despite its cost it seems to me that reverting to static analysis on xe3 is the best trade-off for the time being (see the individual commit messages for compile- and run-time test results broken up by commit).”
After these patches were reviewed the last few weeks via this merge request, the code was merged today for Mesa 25.3-devel. The patches should also end up being back-ported for the Mesa 25.2 stable series considering they are very important performance fixes for Panther Lake.
In the comments to Intel driver engineers discussing these patches, it does look like some GPU hang issues affecting Panther Lake are still being sorted out:
“Here’s the result of my real-game testing. Cyberpunk was excluded because of GPU hang issues. BL3 saw some periodic hangs, but I was able to collect. Warhammer results looks strange, but I did verify them with a second run.”
Hopefully this is all sorted through soon for ensuring a nice Linux experience with Xe3 graphics on Panther Lake in the months ahead.
