Intel vs. Modesetting X.Org DDX Performance Impact

[phoronix]

Phoronix: Intel vs. Modesetting X.Org DDX Performance Impact

With word of Fedora switching away from using the Intel X.Org driver in favor of the generic xf86-video-modesetting driver, following in the steps laid by Debian/Ubuntu, there is fresh discussions over features and any performance impact of xf86-video-modesetting vs. xf86-video-intel DDX drivers. As such, here are some fresh 2D and 3D benchmarks.

http://www.phoronix.com/vr.php?view=24005

[darkbasic]

Modesetting is still much, much slower in several areas. When you hit one of them, you notice the difference (especially on slow GPUs like Intel's). Hope it gets some attention.

[darkbasic]

By the way, please test on xorg-server 1.19. It's useless to test an old version when everybody will get 1.19 soon.

[davidbepo]

thanks for refreshing the fact that SNA IS FASTER
but also that its less important now than before

[pq1930562]

Michael :

Why did you use an old xorg-server version and an old version of xf86-video-intel?

It would have been a lot more interesting if you would have used the latest xorg-server version and the latest git snapshot of xf86-video-intel.

[Sloth]

I retested some of that with current X, mesa, xf86-video-intel (on a current processor, too - Skylake.) These are all straight out of git.

Modesetting is about on par for gtkperf (as I posted yesterday), and for a couple of the worst offenders in Michael's list, intel is much faster still:

intel: 3000000 reps @ 0.0024 msec (422000.0/sec): Fill 300x300 aa trapezoid
modesetting: 20000 reps @ 0.3441 msec ( 2910.0/sec): Fill 300x300 aa trapezoid

And in others, modesetting is greatly improved:

intel: 40000000 reps @ 0.0001 msec (7310000.0/sec): Char in 80-char aa line (Charter 10)
modesetting: 56000000 reps @ 0.0001 msec (10200000.0/sec): Char in 80-char aa line (Charter 10)

My seat-of-pants impression is that I cannot tell any difference, except that modesetting is more stable.

[Michael]

Michael :

Why did you use an old xorg-server version and an old version of xf86-video-intel?

It would have been a lot more interesting if you would have used the latest xorg-server version and the latest git snapshot of xf86-video-intel.

I was using Intel Git, Padoka PPA packages snapshot. I used the current xorg-server as found in Ubuntu. When 1.19 lands or next time I fire up a Fedora system with 1.19, I can deliver more benchmarks.

[pq1930562]

Michael :

You wrote:

The generic mode-setting DDX driver has improved a lot over 2016 with DRI3 support

How did you enable DRI3 on xf86-video-modesetting? Xorg.0.log only mentions DRI2 here, see:

https://bugs.freedesktop.org/show_bug.cgi?id=98875

Does Xorg.0.log say DRI3 on your machine?

[dungeon]

Debian and Fedora disable this for newer not for old.

Why Ubuntu with old X that does not tell nothing, just test Debian or Fedora

[doublez13]

Ok I've got a beginner question here.
I thought that intel's graphics drivers/modules were actually included in the kernel source. So when I install something like xserver-xorg-video-intel, what am I actually installing? are these closed source blobs or something? I didn't think that intel graphics needed anything to be installed. Same with nouveau? What am I missing?
Thanks guys!