Intel Graphics With Linux 6.6 Adds Tuning Knobs That Can Yield 10~15% Better Performance

With new i915 driver code ready for the upcoming Linux 6.6, new threshold tuning around the RPS (cited as both Render P-States and Requested Power States) for some Intel graphics hardware and in some games can yield around a 10~15% boost to performance.

Back in April I wrote about some Intel graphics driver patches allow for tuning up to 10~10% better performance. That work came from Google Chrome OS engineers around allowing the Intel RPS up/down thresholds to be configured by user-space. Google engineer Syed Faaiz Hussain raised the issue that they experimented with the Intel RPS tuning and were able to manage up to 15% better performance. With Counter-Strike: Global Offensive with OpenGL was a 14.5% boost, CS:GO with Vulkan was 12.9% faster, and Civilization VI with OpenGL was 11% faster.

This RPS threshold tuning though is for non-GuC based platforms, thus the very latest Intel integrated and discrete graphics won't have these controls but rather pre-DG2/ADL platforms where GuC isn't used by default. This functionality also depends upon users adjusting their RPS thresholds, though potentially we could see Feral's GameMode integrate support for automatically adjusting these values or similar Linux gaming optimization solutions add support for RPS adjustments when users launch their game collection. With boosting to a higher power state faster though does mean there can be an impact on the power and thermal of the systems.

The RPS threshold patches were finally sent in today to DRM-Next via the new drm-intel-gt-next pull of material for Linux 6.6. In addition to the RPS threshold patches, this pull request has a fix to avoid infinite GPU waits, various Meteor Lake updates, and a variety of other workarounds and fixes added. This drm-intel-gt-next pull request comes just a day after this drm-intel-next pull with additional Intel DRM driver feature work for this upcoming kernel cycle.