Wayland latency tuning - Revision history

Gnif: /* Looking Glass latency tuning (B5-only) */

2023-02-05T11:55:51Z

Looking Glass latency tuning (B5-only)

Quantum at 09:26, 30 August 2021

2021-08-30T09:26:42Z

Quantum at 09:26, 30 August 2021

2021-08-30T09:26:01Z

Quantum at 09:13, 30 August 2021

2021-08-30T09:13:16Z

Quantum: Created page with "On Wayland, frame latency can be reduced by making the compositor render as late as possible before a vblank. This allows the compositor to show the latest frame available, ju..."

2021-08-30T09:04:12Z

Created page with "On Wayland, frame latency can be reduced by making the compositor render as late as possible before a vblank. This allows the compositor to show the latest frame available, ju..."

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On Wayland, frame latency can be reduced by making the compositor render as late as possible before a vblank. This allows the compositor to show the latest frame available, just in time for the screen refresh. This guide describes how to configure this for certain compositors.

Looking Glass can also be made to render right before the compositor renders, further reducing latency. This is what the <code>win:jitRender</code> setting does on Wayland. The timing of this is also controlled by the compositor, and thus the configuration is compositor-specific.

== Sway ==

On Sway, this is controlled by the <code>max_render_time</code> setting. The <code>max_render_time</code> setting on the output controls how many millisecond the compositor renders before the vblank. Setting <code>max_render_time</code> on the window controls how many milliseconds the compositor tells windows to render.

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 We start by running <code>swaymsg output DP-1 max_render_time 1</code>. If there is frame dropping, increase the value of <code>max_render_time</code> by 1 and try again until frame dropping stops. This is the optimal setting for <code>max_render_time</code>. Once you find this value, open up your sway config file (usually <code>~/.config/sway/config</code>), and add the line <code>output DP-1 max_render_time t</code>, with <code>t</code> replaced by the optimal value obtained previously.
-=== Looking Glass latency tuning (B5-only) ===
+=== Looking Glass latency tuning (B5 and later only) ===
 Tuning the latency for Looking Glass follows a very similar process:

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 Tuning the latency for Looking Glass follows a very similar process:
-. Close the Looking Glass client.
+# Close the Looking Glass client.
-. Run <code>swaymsg 'for_window [app_id="looking-glass-client"] max_render_time 1'</code>.
+# Run <code>swaymsg 'for_window [app_id="looking-glass-client"] max_render_time 1'</code>.
-. Run the Looking Glass client with the <code>win:showFPS win:jitRender</code> option. If you have multiple monitors, you want to move to window to the monitor with the highest resolution.
+# Run the Looking Glass client with the <code>win:showFPS win:jitRender</code> option. If you have multiple monitors, you want to move to window to the monitor with the highest resolution.
-. If the FPS value displayed is lower than the screen refresh rate, close the client and restart from step 2, but increment the value of <code>max_render_time</code> by 1.
+# If the FPS value displayed is lower than the screen refresh rate, close the client and restart from step 2, but increment the value of <code>max_render_time</code> by 1.
-. Once this is done, open up your sway config file (usually <code>~/.config/sway/config</code>), and add the line <code>for_window [app_id="looking-glass-client"] max_render_time t</code>, with <code>t</code> replaced by the optimal value obtained previously.
+# Once this is done, open up your sway config file (usually <code>~/.config/sway/config</code>), and add the line <code>for_window [app_id="looking-glass-client"] max_render_time t</code>, with <code>t</code> replaced by the optimal value obtained previously.

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 == Sway ==
-On Sway, this is controlled by the <code>max_render_time</code> setting. The <code>max_render_time</code> setting on the output controls how many millisecond the compositor renders before the vblank. Setting <code>max_render_time</code> on the window controls how many milliseconds the compositor tells windows to render.
+On Sway, this is controlled by the <code>max_render_time</code> setting. The <code>max_render_time</code> setting on the output controls how many millisecond the compositor renders before the vblank. Setting <code>max_render_time</code> on the window controls how many milliseconds the compositor tells windows to render. Both must be set for optimal latency.
 === Screen latency tuning ===
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 We start by running <code>swaymsg output DP-1 max_render_time 1</code>. If there is frame dropping, increase the value of <code>max_render_time</code> by 1 and try again until frame dropping stops. This is the optimal setting for <code>max_render_time</code>. Once you find this value, open up your sway config file (usually <code>~/.config/sway/config</code>), and add the line <code>output DP-1 max_render_time t</code>, with <code>t</code> replaced by the optimal value obtained previously.

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-On Wayland, frame latency can be reduced by making the compositor render as late as possible before a vblank. This allows the compositor to show the latest frame available, just in time for the screen refresh. This guide describes how to configure this for certain compositors.
+On Wayland, frame latency can be reduced by making the compositor render as late as possible before a vblank. This allows the compositor to show the latest frame available, just in time for the screen refresh. This guide describes how to configure this for certain compositors. This will improve your experience for all applications, not just Looking Glass.
 Looking Glass can also be made to render right before the compositor renders, further reducing latency. This is what the <code>win:jitRender</code> setting does on Wayland. The timing of this is also controlled by the compositor, and thus the configuration is compositor-specific.
@@ Line 6: / Line 6: @@
 On Sway, this is controlled by the <code>max_render_time</code> setting. The <code>max_render_time</code> setting on the output controls how many millisecond the compositor renders before the vblank. Setting <code>max_render_time</code> on the window controls how many milliseconds the compositor tells windows to render.