Early Intel i965 vs. Iris Gallium3D OpenGL Benchmarks On UHD Graphics 620 With Mesa 19.1

With yesterday's somewhat of a surprise announcement that Intel is ready to mainline their experimental Iris Gallium3D driver as their "modern" Linux OpenGL driver with numerous design advantages over their long-standing "classic" i965 Mesa driver, here are some fresh benchmarks of that latest driver compared to the current state of their OpenGL driver in Mesa 19.1.

I'll be working on more Intel Iris OpenGL driver benchmarks in the days ahead as yesterday's merge request caught me a bit off-guard, but since then I kicked things off by checking out the Iris driver support using the common UHD Graphics 620 as found on many current generation notebooks/ultrabooks. This Intel OpenGL Linux driver comparison was done with a Dell XPS 9370 featuring an Intel Core i7 8550U Kabylake-R with UHD Graphica 620 that top out at 1.15GHz.

This Dell XPS laptop was using an Ubuntu 19.04 daily snapshot while upgrading to the Linux 5.0 Git kernel and building Mesa 19.1.0-devel from Ken's Iris development branch as of 20 February. This was the first time I tested the Iris Gallium3D driver since last December's benchmarks when originally evaluating the Iris driver performance. Since then the Iris driver has filled in more missing pieces of OpenGL support as well as some performance optimizations, but more work remains.

As outlined in many Phoronix articles now, the Iris driver is exclusively designed for Broadwell "Gen 8" graphics and newer. Those with Haswell graphics and older will not see Iris driver support, but for those users the i965 Mesa driver is remaining within the Mesa tree and will still be supported/used by those older generations of support. Using Iris also requires a sufficiently new kernel, namely Linux 4.16 and newer.

Overall from this latest Iris open-source driver testing I did overnight, it's in better shape than my testing from December. There still are some areas where the older i965 driver remains faster, but that's to be expected since the Intel Open-Source Technology Center crew haven't exhausted all their optimization work yet but in fact just getting started in squeezing more performance potential out of this Gallium3D-based driver.

For today's tests I ran various Linux OpenGL games and synthetic tests that worked fine for the UHD Graphics 620. Tests on other hardware coming up soon but the situation should get really interesting later this year with Icelake graphics having much more graphics horsepower followed by the first of Intel's discrete GPU offerings in 2020.

This testing was done using the development Iris branch of Mesa but already with today's Mesa 19.1 Git, the driver has landed and more tests of that mainline code will be on the way.