KDE + Nvidia = Tearing

[xazero]

Hi all

Ive been experiencing tearing (whole screen not only xv), when composite is enabled and the nvidia drivers installed, even if i have vsync turned on .


also i have to say that if i enable the snow effect the tearing completely disappears and the fps plugin says kwin is running exactly at 61 fps (which is the right value) but if i turn of the snow effect the tearing eventually comes back.
that makes me think that only opengl apps are getting the vsync. (and the snow effect makes the whole desktop to be opengl drawn i guess).

i know that this is probably not a nvidia bug but no one have been able to help me in the kde forums nor in the ubuntu forums.

http://forum.kde.org/viewtopic.php?f=15&t=88200
http://ohioloco.ubuntuforums.org/sho....php?t=1493721

HW:macbook pro 5,5
-GPU: nvidia geforce 9400m

SW: Kubuntu 10.04
-nvidia drivers: 195.36.15
-Xorg(server vendor version): 1.7.6
-KDE SC: 4.4.3
-QT:4.6.dontknow

Config:

-xorg.conf

...
Option "NoLogo" "True"
Option "TripleBuffer" "True"
Option "DynamicTwinView" "False"
Option "BackingStore" "True"
Option "RenderAccel" "True"
Option "DamageEvents" "True"
Option "PixmapCacheSize" "1024000"
Option "AddARGBGLXVisuals" "True"
Option "AllowIndirectPixmaps" "True"
...
Driver "nvidia"
...

-~/.xinitrc

export __GL_SYNC_TO_VBLANK=1
#export QT_GRAPHICSSYSTEM=opengl ##I KNOW IT DOESN'T WORK BUT I WISH IT DID
nvidia-settings --load-config-only
nvidia-settings -a InitialPixmapPlacement=2 -a GlyphCache=1
. /etc/X11/xinit/xinitrc

kwinrc

[Compositing]
AnimationSpeed=2
Backend=OpenGL
CheckIsSafe=true
DisableChecks=true
Enabled=true
GLDirect=true
GLMode=TFP
GLTextureFilter=2
GLVSync=true
HiddenPreviews=6
RefreshRate=60
UnredirectFullscreen=true
#XRenderSmoothScale=true
...

.nvidia-settings-rc

...
0/SyncToVBlank=1
...
0/OpenGLImageSettings=1 # dont know what's this for
...
0/XVideoTextureSyncToVBlank=1
...

[thefirstm]

You might want to check on PowerMizer to see what it is doing while you get the tearing. With my card, compositors will tear horribly unless the GPU is in its highest performance mode, which is induced by launching an OpenGL application.

[xazero]

Originally Posted by thefirstm

You might want to check on PowerMizer to see what it is doing while you get the tearing. With my card, compositors will tear horribly unless the GPU is in its highest performance mode, which is induced by launching an OpenGL application.

Thanks, i changed the preferred mode to maximum performance and it actually seems to be helping somehow.
But i just realized that if i run glxgears the kwin fps plugin reports ~30 fps while
the output of glxgears reports ~300 frames per 5 seconds (~60fps) that makes me think that kwins vsync and
nvidias vsync dont get along.

any thoughts?

[Dragoran]

Originally Posted by xazero

Thanks, i changed the preferred mode to maximum performance and it actually seems to be helping somehow.
But i just realized that if i run glxgears the kwin fps plugin reports ~30 fps while
the output of glxgears reports ~300 frames per 5 seconds (~60fps) that makes me think that kwins vsync and
nvidias vsync dont get along.

any thoughts?

Well 30 fps indicates that there is a double wait ... i.e enable either kwin's sync to vblank or enable at the driver level but not *both*.

[ledoc]

Something I would definitely start with is to scrap ALL the weird, partially obsolete and conflicting extra settings in ALL the config files you quoted.

[xazero]

Originally Posted by ledoc

Something I would definitely start with is to scrap ALL the weird, partially obsolete and conflicting extra settings in ALL the config files you quoted.

can you place be more specific?


export __GL_SYNC_TO_VBLANK=1 #If you have vsync enabled in the nvidia settings this gets exported anyway
nvidia-settings --load-config-only #making sure the settings load
nvidia-settings -a InitialPixmapPlacement=2 -a GlyphCache=1 # from the kde website, to make plasma smoother

Option "TripleBuffer" "True" #make gl to be triple buffered
Option "DynamicTwinView" "False" # fixes the xrandr/nvidia problem (without this kwin tries to run at 50 fps)
Option "BackingStore" "True" # on by default
Option "RenderAccel" "True" # on by default
Option "DamageEvents" "True" # on by default
Option "PixmapCacheSize" "1024000" #increasing cache size
Option "AddARGBGLXVisuals" "True" # on by default
Option "AllowIndirectPixmaps" "True" # on by default

as for kwinrc and nvidia-settings-rc everything comes from the gui

[xazero]

Originally Posted by Dragoran

Well 30 fps indicates that there is a double wait ... i.e enable either kwin's sync to vblank or enable at the driver level but not *both*.

thanks for helping

but i have a problem that goes beyond that
(and i have this exact problem in two computers)

more info:

kwin vsync on, nvidia vsync on:

kwin goes at 60 fps as long as i have an opengl effect running
glxgears 60 fps (but kwin gets only 30 fps (double waiting?))

kwin vsync on, nvidia vsync off:

kwin ~50-60 (60 most the time) (still tearing)
glxgears 60 fps (kwin ~30 fps (double wait))

kwin vsync off, nvidia vsync on:

kwin ~100 fps (nvidia vsync not working?)
glxgears 60 fps (kwin 30-62 fps (WTF?))


kwin vsync off, nvidia vsync off:

kwin ~100 fps
glxgears ~55 fps (kwin ~30-55 fps)
__GL_SYNC_TO_VBLANK=1 is making glxgears to vsync? (see PS!)

PS
for the tests i disabled triplebuffering in xorg.conf
and commented the __GL_SYNC_TO_VBLANK=1 in my xinitrc but somehow it
still gets loaded acording to printenv.
and before each test i restarted X.


Im going somehow to disable the __GL_SYNC_TO_VBLANK=1 and post back later