screen tearing 16.04 fixed using Xrender

[woodsmoke]

Using a Radeon 7570 video card with modern AMD 6 cpu computer on a newly installed Kubuntu 16,04 system after updates I began experienceing "screen tearing" as of the date of this post when running Firefox.

The visual representation was that the wallpaper would display as disparate "boxes" showing through Firefox.

Moving FF would "usually" rectify the situation, but also, sometimes create a new box. The boxes were very "smooth" and had distinct "right angle corners", not the normal "tearing" as a sheet going from side to side.

As with KDE Neon on a much less powerful system, the solution was to change from OpenGl to Xrender in settings/display and monitor / Compositor / Rendering backend.

If anyone has questions please ask.

woodsmoke

[woodsmoke]

I go "back and forth" with a bunch of stuff such as changing the drivers in and out etc.

Yesterday after a relatively large update in Kubu LTS I shifted back through the Open Gl drivers, 2.0 and 3.1 and got really MASSIVE tearing , as in great huge hunks of an "app" on the screen using 2.0.

except THIS WAS DIFFERENT....

huge, horizontal SECTIONS which went horizontally across the screen with similarly sized gaps between them.

Almost like the old "raster scan" gone wild. ...dunno..

I got a "few" tears with 3.1 and none with xrender

so, something is going on upstream, don't know what.

woodsmoke

[ubuntuku]

Running kde neon with amd radeon r9 270x, I fixed the issue by upgrading kernel to 4.13, now I can use opengl without tearing . Optionally update the graphics driver from

ppa:ubuntu-x-swat/updates or ppa:oibaf/graphics-drivers