====== Ubuntu - GPU - AMD GPU - Troubleshooting - Screen Tearing ======

Screen tearing is an effect seen in moving pictures where the display suffers from distortion due to incorrect rendering of fast-changing images

  * Screen tearing occurs when the monitor’s refresh rate and GPU’s frame rate are not synchronized.
  * It is characterized as a horizontal split at one or more places in the image.

Screen tearing can be fixed by enabling VSync, Adaptive VSync, Enhanced Sync, Fast Sync, FreeSync, G-SYNC or Variable Refresh Rate, depending on what the PC system and monitor support.

----

===== GPU Config File Update =====

Edit (or create) the Xorg config file in the **/usr/share/X11/xorg.conf.d/** directory.

  * If using a newer AMD GPU, the file is probably the one named **10-amdgpu.conf**.

<file bash /usr/share/X11/xorg.conf.d/10-amdgpu.conf>
Section "Device"
    Identifier "AMDgpu"
    MatchDriver "amdgpu"
    Driver "amdgpu"
    Option "TearFree" "true"
EndSection
</file>

  * If using an older AMD GPU, the file is probably the one named **10-radeon.conf**.

<file bash /usr/share/X11/xorg.conf.d/10-radeon.conf>
Section "Device"
    Identifier "Radeon"
    MatchDriver "radeon"
    Driver "radeon"
    Option "TearFree" "true"
EndSection
</file>

<WRAP info>
**NOTE:**  The key here is the **TearFree** option.

  * This configuration is effective for many different systems
  * It mmay work with Xorg-server or Wayland.

</WRAP>


----

===== Restart the X server =====

<code bash>
restart gdm
</code>

<WRAP info>
**NOTE:**  Be sure to save any work and close applications first, as this will log out any users utilizing the graphical front-end.
</WRAP>

----

===== Alternative configuration utilizing DRI =====

A modified version of the configuration may also improve performance, by utilizing **DRI** (direct rendering infrastructure) 3.

  * This has certain improvements for the way the X server handles rendering.
  * Also enabling Glamor (if not enabled already by default) can  improve 2D rendering tasks, performing them through Mesa’s OpenGL libraries.
    * Older AMD cards will not support Glamor.
  * The enhanced configuration is as follows:

<file bash /usr/share/X11/xorg.conf.d/10-amdgpu.conf>
Section "Device"
    Identifier "AMDgpu"
    MatchDriver "amdgpu"
    Driver "amdgpu"
    Option "TearFree" "true"
    Option "DRI" "3"
    Option "AccelMethod" "glamor"
EndSection
</file>

or

<file bash /usr/share/X11/xorg.conf.d/10-radeon.conf>
Section "Device"
    Identifier "Radeon"
    MatchDriver "radeon"
    Driver "radeon"
    Option "TearFree" "true"
    Option "DRI" "3"
    Option "AccelMethod" "glamor"
EndSection
</file>

----

===== Check the current TearFree status =====

<code bash>
xrandr --verbose | grep "TearFree"
</code>