When i run an opengl app in full screen (either real full screen or "Alt-F11") opengl apps stutters about once per second when "Allow Flipping" is enabled in nvidia-settings. This do not happen in a kde session. How to reproduce: - start xfce - enable "Allow Flipping" in nvidia-settings - start glxgears and make it full screen (Alt-F11) - watch the stuttering when glxgears is in fullscreen My config: - archlinux with standard xfce 4.6.1 - nvidia 9800GTX+ using 190.25 driver
xfwm4 has nothing to do with OpenGL and does not use OpenGL for compositing at all, it's hardly related to the window manager.
works just fine with intel driver btw.
i had to select one category so i choose the window manager, please place in a better category if possible some xfce dev with nvidia should at least be interested in reproducing this since its no stuttering in kde
btw, i have no composition enabled
There are more tests you may want to pursue, like replacing a component at at time, while still in xfce. For example, start with the window manager: - open a terminal - try metacity $ metacity --replace & - see if you experience the same issue - retry with kwin $ kwin --replace & - see if you experience the same issue (you may want to try with other window managers too) Make sure all tests are performed the same way, ie disable all compositing in all 3 (including of course kwin). Again, I don't see this being related to the window manager but I could be wrong of course :)
I was able to track the cause down to the CPU Graph panel plugin. After i killed the panel exited xfce now at login the panel restarts a number of times (~5) before xfce is fully up, i hope i can fix this now but if you have any tip how to fix it is most welcome.
I solved the panel restart issue by deleting everything in ~/.cache/sessions/. Sorry for spamming :).
I tried the System Load Monitor panel plugin and i see the stuttering so maybe this is a panel problem.
Neither the panel itself or panel plugins have anything to do with OpenGL, so the bug most likely lies elsewhere. Sorry that we are not able to help, but as nobody on our side has reproduced this bug, there is little we can do. If the bug persists, I suggest you look more towards the video driver than towards XFCE, unless you manage to clearly isolate which xfce component causes this.
I have replaced xfce panel with tint2 so i will not follow this so much now. If it is universal problem and not only with nvidia driver on archlinux i suppose you will hear about this problem later. In case you are interested and i did not explain how to reproduce here is how: - nvidia binary driver with default config (nvidia-xconfig) - check "allow flipping" and "sync to vblank" in nvidia-settings - add a graphical applet to panel - start glxgears and switch it to full-screen (Alt-F11) If i do this i will get a stutter in glxgears about once every second.
Thank you for the information you provided, and sorry for not being able to help this time. Hopefully, it was an isolated issue that does not reproduce in other setups, but if it turns out to be common, your input should help narrow down what is happening.