Enabling DRI3 Is Still An Easy Performance Hack Relevant For Ubuntu 16.04 Systems

[tomtomme]

DRI setting in xorg.conf doesn't matter and is ignored (at least on my machine).

Use this:

$ LIBGL_DEBUG=verbose vblank_mode=0 fgl_glxgears (with "glxgears" it's unclear whether there's a difference in FPS)
Using GLX_SGIX_pbuffer
libGL: pci id for fd 4: 1002:67b1, driver radeonsi
libGL: OpenDriver: trying /usr/lib64/dri/tls/radeonsi_dri.so
libGL: OpenDriver: trying /usr/lib64/dri/radeonsi_dri.so
libGL: Using DRI3 for screen 0
10820 frames in 5.0 seconds = 2164.000 FPS
12168 frames in 5.0 seconds = 2433.600 FPS
12175 frames in 5.0 seconds = 2435.000 FPS
12172 frames in 5.0 seconds = 2434.400 FPS

$ LIBGL_DEBUG=verbose LIBGL_DRI3_DISABLE=foo vblank_mode=0 fgl_glxgears
Using GLX_SGIX_pbuffer
libGL: OpenDriver: trying /usr/lib64/dri/tls/radeonsi_dri.so
libGL: OpenDriver: trying /usr/lib64/dri/radeonsi_dri.so
libGL: Using DRI2 for screen 0
10036 frames in 5.0 seconds = 2007.200 FPS
11491 frames in 5.0 seconds = 2298.200 FPS
11494 frames in 5.0 seconds = 2298.800 FPS
11493 frames in 5.0 seconds = 2298.600 FPS

http://www.mesa3d.org/envvars.html

yeah. so this way you can disable dri3.
but we want to enable it...

[c2h5oh]

AFAIK Ubuntu, including 16.04, has disabled DRI3 for Intel on driver level. Luckily this is not the case with Oibaf drivers.

on IRIS PRO 5200 (i7 4770 HQ):

DRI2

36912 frames in 5.0 seconds = 7382.266 FPS
37524 frames in 5.0 seconds = 7504.784 FPS
37587 frames in 5.0 seconds = 7517.308 FPS

DRI3

43628 frames in 5.0 seconds = 8725.515 FPS
45758 frames in 5.0 seconds = 9151.523 FPS
44552 frames in 5.0 seconds = 8910.336 FPS

Solid 20%

[Nille_kungen]

DRI setting in xorg.conf doesn't matter and is ignored (at least on my machine).

Use this:

$ LIBGL_DEBUG=verbose vblank_mode=0 fgl_glxgears (with "glxgears" it's unclear whether there's a difference in FPS)
Using GLX_SGIX_pbuffer
libGL: pci id for fd 4: 1002:67b1, driver radeonsi
libGL: OpenDriver: trying /usr/lib64/dri/tls/radeonsi_dri.so
libGL: OpenDriver: trying /usr/lib64/dri/radeonsi_dri.so
libGL: Using DRI3 for screen 0
10820 frames in 5.0 seconds = 2164.000 FPS
12168 frames in 5.0 seconds = 2433.600 FPS
12175 frames in 5.0 seconds = 2435.000 FPS
12172 frames in 5.0 seconds = 2434.400 FPS

$ LIBGL_DEBUG=verbose LIBGL_DRI3_DISABLE=foo vblank_mode=0 fgl_glxgears
Using GLX_SGIX_pbuffer
libGL: OpenDriver: trying /usr/lib64/dri/tls/radeonsi_dri.so
libGL: OpenDriver: trying /usr/lib64/dri/radeonsi_dri.so
libGL: Using DRI2 for screen 0
10036 frames in 5.0 seconds = 2007.200 FPS
11491 frames in 5.0 seconds = 2298.200 FPS
11494 frames in 5.0 seconds = 2298.800 FPS
11493 frames in 5.0 seconds = 2298.600 FPS

http://www.mesa3d.org/envvars.html

fgl_glxgears is from catalyst and i haven't used it in a long time but if you use the open radeon driver then DRI 3 will work if your graphics stack is recent enough.

[tomtomme]

This is how it is in my xorg.conf and I've been using it for the last year no problems. Worthwhile for sure.

thx bro. your xorg.conf works for me, radeonSI, AMD A8 7600 APU with openSUSE Tumbleweed. glxgears reports dri3 with

Option "DRI3" "1"

while it did report dri2 before I added that.

[theriddick]

Yeah DRI3 still only gives me ~22fps in warthunder@4k with med-high settings (no blur or fsaa) on my 390x.
When I had my 980GTX I was getting 50-70fps with everything on high (no blur or fsaa) at 4k.

I had a problem with vsync being forced on regardless of settings, might rerun my tests once I get that forced off. (the game had it off)

[mannerov]

Yeah DRI3 still only gives me ~22fps in warthunder@4k with med-high settings (no blur or fsaa) on my 390x.
When I had my 980GTX I was getting 50-70fps with everything on high (no blur or fsaa) at 4k.

I had a problem with vsync being forced on regardless of settings, might rerun my tests once I get that forced off. (the game had it off)

Seems a strange performance.
Perhaps try with gallium nine under wine to see if that helps ?

[theriddick]

I don't know how well it will work under wine, I am running at 3840x2160 which might cause vram issues under wine. Anyway I will try and force disable vsync and test again, then test under amdgpu, THEN test under amdgpu-pro if I can get it installed.

Well I tried the amdgpu lot, and with dri3 enabled. Unfortunately the whole screen is tearing and wobbling all over the place so I have no idea what the problem is (4k issue?). The standard radeon driver didn't do this! I did do one lot of tests with amdgpu (not pro) and got 10-15fps so something is definitely broken.

[Pander]

What is the url of the bug at Launchpad? Moving these improvements to there will speed up the process.

[lowflyer]

does anybody know what the "issues" are with DRI3 ? I only found this about Nouveau. How about Radeon?