Even In 2021, Intel Squeezes Some Very Nice Performance Gains Out Of Their OpenGL Driver

While it's 2021 and many modern Linux gaming and other workloads are focusing on the Vulkan API, Intel isn't letting up in their aggressive optimizations to their open-source "Iris" OpenGL Gallium3D driver for Linux systems. With the latest Mesa 21.1 code today there is a set of patches providing up to 17% better performance in some games while other OpenGL software is generally a few percent faster at least. In some micro-benchmarks it can be more than 50% faster.

Longtime Intel open-source Linux graphics driver developer Kenneth Graunke - who has also been the lead Iris Gallium3D developer over the past three years - merged his work on threaded context support.

With the "u_threaded_context" support merged today to Mesa 21.1-devel, the game Civilization VI is now running 17% faster, Shadow of Mordor and Bioshock Infinite each 6% faster, and even Xonotic clocks in at 6% faster. Meanwhile micro-benchmarks like GfxBench and SynMark are more than 50% faster. These are some impressive gains and I'll be firing up various benchmarks on different Intel Linux graphics systems shortly.

The u_threaded_context functionality for Gallium3D was originally written by AMD for their Gallium3D driver code. The u_threaded_context allows for writes to the command stream to be handled asynchronously off of the main application thread. A few months ago the Zink code began making use of u_threaded_context and now Intel's Iris is as well to great performance success thanks to the extra threading / avoiding driver overhead.

The Intel Iris u_threaded_context support was merged today across the span of several commits in first needing to make the driver more thread-safe. This exciting addition is part of next quarter's Mesa 21.1 release. The GALLIUM_THREAD=0 environment variable can be used for disabling the threaded context behavior if wanting to compare the performance impact as this functionality is enabled by default. Benchmarks soon!