Iris in Production
In rapid development with changes happening every day. Usable for adventurous users and testers. Not conformant yet. The hope is to have it be the preferred driver for Icelake and Gen11+.
We hope it will be a viable replacement for i965 by the Mesa 19.2 release (August) for bleeding edge / less risk-averse users, and the default driver by the end of the year.
How to try it
Be sure you are using Kernel 4.18.11 or 4.19 or later. (Kernel 4.18.10 and older have memory leaks which iris will provoke.)
Simply export MESA_LOADER_DRIVER_OVERRIDE=iris before running your game, or download a wrapper script and run iris glxinfo.
If the GL_VENDOR string reports "Intel", you are using the new iris driver. If it reports "Intel Open Source Technology Center", you are using the older i965 driver.
$ glxinfo | grep 'GL vendor' OpenGL vendor string: Intel Open Source Technology Center $ MESA_LOADER_DRIVER_OVERRIDE=iris glxinfo | grep 'GL vendor' OpenGL vendor string: Intel
This is sufficient to try it out for individual programs. If you want X/Glamor to use it, additional steps are required - X currently always looks for i965_dri.so.
- Seems to have memory leaks on long running programs
- Steam client misrenders
- E2E color compression (Y+CCS modifier) missing
- ASTC 5x5 and void extent workarounds missing
- xorg-server's PCI ID map still prefers i965
- See the Bugzilla Bug List
We have not gone through the official OpenGL or OpenGL ES conformance submission process yet. We are passing 95% or more of Piglit, dEQP, and the GL/GLES CTS tests.
We've tested the following games:
- Bioshock Infinite
- Civilization VI
- DiRT Rally
- Shadow of Mordor
- Tomb Raider
- XCOM 2: War of the Chosen
- Child of Light
Iris has dramatically lower CPU overhead than i965 - it can issue on average 5x more draw calls per second.
Many programs are 10-15% faster on Iris, but some are still around 10% slower. We are working to close these gaps; let us know if you find any.
Performance counter support is in progress.
See the most recent numbers on Phoronix.
- fp64 emulation may not be hooked up yet (Dave and Jordan have patches).
- Otherwise should be on par with i965 or better.
Iris supports generally the same feature set as i965, with a few differences. The intention is to close this gap so Iris supports everything and then some.
- GL_ARB_compatibility in OpenGL 3.1
- GL_ARB_texture_buffer_object in legacy GL
- GL_ARB_texture_buffer_object_rgb32 in legacy GL
May not be worthwhile, no one uses it and Intel is the only vendor supporting it.