[SOLVED] Really weird graphics glitches on 15.04 [KDE]

[Guest]

I've been noticing since I upgraded to 15.04 some really strong and weird graphics glitches. Its hard to explain so I just made a video:

Basically, the windows get like "stuck", if I minimize a window, its still displayed partially (broken), but unusable... making another click makes the ghost window dissappear. There are also gliches when going from one virtual desktop to the next one. Windows stay and then it flickers back and forth between the real window and the ghost one sometimes getting stuck for a while. Making several clicks around tends to stabilize the situation but it occurs again every time.

First, it happened on an upgraded installation. But then I did a clean install and same thing.

I have an ATI Radeon HD 5456. I tried both with open source, and proprietary drivers and the problem persisted.

Any ideas what could it be? Maybe faulty graphics board? Incompatible? Its really strange, and it makes it very difficult for me to work...

Thanks a lot!!!

[Guest]

Hi rafadev,

I noticed similar glitches using intel i3 cpu with integrated GPU using a clean installation and without virtual desktop. The only similarity was that I had connected an external display using a VGA cable on my laptop. Maybe Plasma isn't yet optimized for multiple screens.

The issues disappear when only using a single display on my machine.

[Guest]

I found the real culprit of the tearing or "glitches" in plasma 5. It is due to the default settings for the desktop effects. If you open 'settings' -> 'Display and Monitor' -> 'Compositor' for the 'Tearing prevention ("vsync")' option set it to 'never', the graphic glitches then disappear for dual screen configuration.

M.

[Guest]

Hey Moonwave! I actually solved it long ago with the same solution, it was my bad forgetting to post it here... thank you!!