Enable G-SYNC

For better performance and to keep up with the high refresh rate of Holoscan applications, we recommend the use of a G-SYNC display.

Follow these steps to ensure G-SYNC is enabled on your display:

1. Open the “NVIDIA Settings” Graphics application (nvidia-settings in Terminal).

2. Click on X Server Display Configuration then the Advanced button. This will show the Allow G-SYNC on monitor not validated as G-SYNC compatible option. Enable the option and click Apply:

   

3. To show the refresh rate and G-SYNC label on the display window, click on OpenGL Settings for the selected display. Now click Allow G-SYNC/G-SYNC Compatible and Enable G-SYNC/G-SYNC Compatible Visual Indicator options, then click Quit. This step is shown in the image below. The G-SYNC indicator is at the top right of the screen once the application is running.

   

4. On an X11 desktop the driver only engages G-SYNC for a fullscreen window it can flip rather than composite, so the indicator in the top-left corner has to read FLIP (not BLIT). On Ubuntu GNOME the AppIndicator extension’s legacy tray keeps every window composited; turn it off with gsettings set org.gnome.shell.extensions.appindicator legacy-tray-enabled false. The G-SYNC panel also has to be the only active output on the X screen, and the application’s frame rate has to stay inside the panel’s variable-refresh range. When the target panel is not the primary output, export __GL_SYNC_DISPLAY_DEVICE=<output> before launching the application (the driver reads it once, when Vulkan first loads; Holoscan operators do not set it). The Holoscan visualization module README (“Fullscreen windows and G-Sync/VRR”) lists the full set of conditions.