Intel Iris Pro 6200 Graphics - i965 vs. Iris Gallium3D OpenGL Performance
With the initial Iris Gallium3D driver that was merged into Mesa at the end of February from our tests on UHD Graphics the performance is quite promising considering the early stage of this new open-source OpenGL driver and it not yet being fully tuned/optimized. The Iris Gallium3D driver support goes back to Broadwell CPUs so I decided to run some benchmarks with the legendary Core i7 5775C that features the Iris Pro Graphics 6200 with 128MB of eDRAM.
While the i7-5775C is an older processor, it remains interesting for having the socketed Iris Pro graphics with onboard eDRAM. The "Iris" Gallium3D driver isn't at all limited to the Intel Iris graphics as we've already shown, just is utilizing the same name for the Gallium3D driver to avoid any confusion with the older "i965" driver that supports back to the Intel 965 IGP generation. The i965 Mesa driver will continue to be maintained for supporting pre-Broadwell Intel graphics while Iris is what's focused on for Broadwell and newer, including Icelake Gen 11 graphics due out later this year.
Besides comparing the i965 vs. Iris performance on the Core i7 5775C, while having this Broadwell system powered up I ran also some other kernel/Mesa combinations for seeing how the performance has evolved recently. The OpenGL test scenarios were:
Linux 4.18 + Mesa 18.2.2 - The out-of-the-box Intel graphics stack with Ubuntu 18.10.
Linux 4.18 + Mesa 18.3.3 - Upgrading Ubuntu 18.10 to the current Mesa 18.3 stable release, soon to be replaced by Mesa 19.0.0.
Linux 4.18 + Mesa 19.1-devel - Upgrading to the current Mesa 19.1-devel release using the Oibaf PPA on Ubuntu.
Linux 5.0 + Mesa 19.1-devel - The same bleeding-edge Mesa code with i965 driver while switching over to the Linux 5.0 kernel for the newer DRM driver code.
Linux 5.0 + Mesa 19.1-devel - Iris - The same configuration as above with the Linux 5.0 kernel and Mesa 19.1-devel via the Oibaf PPA but having switched to the Iris Gallium3D driver. Those using Mesa 19.1 Git can easily activate this alternative driver via the MESA_LOADER_DRIVER_OVERRIDE=iris environment variable.
Through this testing of all the open-source Intel driver combinations, the Iris Pro Graphics 6200 were working out well and encountered no issues -- including with the Iris Gallium3D driver. Via the Phoronix Test Suite various OpenGL benchmarks were carried out on this still capable system.