How to Enable Intel DRI3 in Xorg
The Direct Rendering Infrastructure (DRI) is a framework for allowing direct access to graphics hardware under the X Window System in a safe, efficient way. The main use of DRI is to provide hardware acceleration for the Mesa implementation of OpenGL. [Wikipedia]
You may be experiencing some graphical glitch effects on your DE, this might be the cause – DRI3 not loaded. How to check this:
$ cat /var/log/Xorg.0.log | grep DRI3 [ 24.608] (II) intel(0): direct rendering: DRI2 DRI3 enabled
If the command returns nothing, this means DRI3 is not loaded.
How to Enable DRI3
Create this file (/etc/X11/xorg.conf.d/20-intel.conf) and add this to its content
Section "Device" Identifier "Intel Graphics" Driver "intel" Option "AccelMethod" "sna" Option "TearFree" "true" Option "DRI" "3" EndSection
Save and reboot, I hope this solves your problem.