Well, I've searched for this variable, and for tearing issues on Ubuntu with NVidia adapters. There are multiple reports and many solutions provided. At least I know the direction for further investigations. Thank you, Sean.
On Tue, Jan 13, 2015 at 10:21 PM, Sean Harmer <sean.har...@kdab.com> wrote: > On Tuesday 13 January 2015 23:06:40 Dmitry Volosnykh wrote: > > Sean, thanks for your input. > > > > I have NVidia GeForce 9800M GTX, and VSync is enabled. Double-checked > that. > > Another enabled options: Allow Flipping and Use Conformant Texture > > Clamping. Do not know what are they for... > > > > Regarding your question about monitor's refresh rate. Here is xrandr's > > output: > > $ xrandr > > Screen 0: minimum 8 x 8, current 1680 x 1050, maximum 8192 x 8192 > > DVI-D-0 disconnected (normal left inverted right x axis y axis) > > LVDS-0 connected 1680x1050+0+0 (normal left inverted right x axis y axis) > > 331mm x 207mm > > 1680x1050 59.9*+ > > DVI-D-1 disconnected (normal left inverted right x axis y axis) > > HDMI-0 disconnected (normal left inverted right x axis y axis) > > > > I guess, it means runs on 60Hz refresh rate. > > Hmm OK if that didn't work, can you try this trick. Try setting > > export __GL_YIELD="USLEEP" > > for your X environment. I have this set in /etc/profile.d/tearing.sh on > Gentoo. > Not sure where the correct place is on Ubuntu. If this is set when X starts > this solves the tearing for me on nVidia when using a compositing window > manager. > > Cheers, > > Sean > > > > > On Tue, Jan 13, 2015 at 9:35 PM, Sean Harmer <sean.har...@kdab.com> > wrote: > > > On Tuesday 13 January 2015 17:02:40 Dmitry Volosnykh wrote: > > > > I've tried to capture the issue: see http://youtu.be/KUNyk2YWBaY > > > > The flickering is more obvious in this video since capturing software > > > > affecting performance. When running application with no video > recording > > > > there's no visual artifacts for about 15 seconds. Then the top of the > > > > > > green > > > > > > > bar visually looks like be shifted leftwards by a small offset which > > > > > > holds > > > > > > > on form the moment of its appearance. The height of this 'cap' may > > > > > > slightly > > > > > > > increase over time. This issue reproduces constantly. > > > > > > Sounds like a lack of v-sync is causing tearing and over time the > offset > > > between the swapbuffers and screen refresh is changing. Is your monitor > > > running > > > at a standard refresh rate? > > > > > > Try forcing vsync in the control panel for your graphics card driver. > At > > > least > > > nVidia provide an option for this. I'm not sure about AMD and Intel. > > > > > > Cheers, > > > > > > Sean > > > -- > > > Dr Sean Harmer | sean.har...@kdab.com | Managing Director UK > > > Klarälvdalens Datakonsult AB, a KDAB Group company > > > Tel. Sweden (HQ) +46-563-540090, USA +1-866-777-KDAB(5322) > > > KDAB - Qt Experts - Platform-independent software solutions > > > _______________________________________________ > > > Interest mailing list > > > Interest@qt-project.org > > > http://lists.qt-project.org/mailman/listinfo/interest > > -- > Dr Sean Harmer | sean.har...@kdab.com | Managing Director UK > Klarälvdalens Datakonsult AB, a KDAB Group company > Tel. Sweden (HQ) +46-563-540090, USA +1-866-777-KDAB(5322) > KDAB - Qt Experts - Platform-independent software solutions >
_______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
