The Current Intel "Iris" Gallium3D OpenGL Performance Against i965 Mesa, Windows 10 OpenGL

[Eero]

Looking at the bad GpuTest Triangle results...

Phoronix uses 60s run-time for GpuTest tests, and the reported score is simply number of rendered frames, so one can get FPS just by dividing score with 60.0. Which is very low for the Triangle test that on every frame just clears the window and draws single half screen sized triangle. Because shader used in the test is trivial, test is memory bandwidth limited.

I know that:
* Windows doesn't composite fullscreen windows (at least with Intel GPUs)
* On my own machines that are running 18.04 with Unity, they don't get composited either, and I get same performance as on Windows (with Git versions of Mesa & X) with the Fullscreen Triangle test, and in windowed version, Linux is faster
* Ubuntu 19.04 has new enough X server (>= 1.20.1) and Mesa (>= 18.1) that it supports end-to-end render buffer compression out of the box on GEN9

So only conclusion is that Michael's setup composites even fullscreen windows. Composition (more than) doubles the bandwidth required for the Triangle test, which would explain half of the expected performance.

This is going to have impact also in other memory bandwidth limited (= most high FPS) tests. Comparisons against Windows should use desktop environment that disables composition in fullscreen, like Windows does.

[FireBurn]

I guess putting

MESA_LOADER_DRIVER_OVERRIDE=iris

into your

/etc/environment

should do

This patch from Kayden should get it working for you as default - also allows you to not compile i965 or clasic in Mesa https://gitlab.freedesktop.org/kwg/m...dcb631a73d4903

Be warned though vaapi doesn't work quite right yet due to some EGL stuff (my memory if failing me) not being implemented yet

[treba]

Is it possible to activate Iris globally even for a compositor like kwin? I would like to compare the experience on my Intel notebooks.

I guess putting

MESA_LOADER_DRIVER_OVERRIDE=iris

into your

/etc/environment

should do

[R41N3R]

Is it possible to activate Iris globally even for a compositor like kwin? I would like to compare the experience on my Intel notebooks.

[treba]

Thanks for running these, Michael! It's always really nice to have an extra set of data about how we're doing.

I fixed Portal, it's now 3.86% faster than i965 on my laptop. Hadn't looked at that one until I saw this.

Nice

Will we that go into 19.1? I really looking forward to give Iris a try as soon as 19.1 arrives in Fedora

[Kayden]

Thanks for running these, Michael! It's always really nice to have an extra set of data about how we're doing.

I fixed Portal, it's now 3.86% faster than i965 on my laptop. Hadn't looked at that one until I saw this.

[grigi]

"as bad" or 'as good' as you thought? 😕

Literally as bad. As in my experience on Windows was abysmal ito performance and stability. Whereas Linux is surprisingly performant on the Intel igp.

Since Broadwell (gen8) , the intel gpus was about on par feature wise. Older iGPs were even worse for their spec level. The last one that had comparable specs was the original 740/815 integrated but that is over two decades ago.
Then the releases later on was mostly incremental fixes, would have loved more than 24SU for a mobile variant, they kinda got stuck at 48 for a long while (after being at 72 during broadwell). (ramble, ramble, ramble…)

[Jabberwocky]

Intel's open source drivers as always worked well for me. The hardware does not have much throughput, but I have the enjoyed low latency in low-demanding space like 2D graphics.

I don't understand the announces of new generation hardware if it doesn't really perform much better than previous generations. Iris Pro Graphics 5200 was the last Intel GPU that greatly improved compared to it's previous generation IMO. It was released more than 5 years ago. June 2018 Intel confirmed discrete GPUs for 2020 (just after hiring Raja). Years from 2020 are starting to turn into months and no promotions going on AFAIK.

I would really like to see something from Intel that is able to compete with the rest of the gaming (not-A.I.) market on a software and hardware level.

Michael, I appreciate the tests. Thanks.

[Michael]

Is there any reason you didn't use the 25.20.100.6618 windows driver?

The one from Intel.com? It said not compatible with this laptop or whatever the precise error message was along those lines.

[FireBurn]

Is there any reason you didn't use the 25.20.100.6618 windows driver?