# Variable Refresh Rate API

The Variable Refresh Rate API allows you to change the current display refresh rate. The API provides `IVariableRefreshRate.SupportedRefreshRates`, an array of display refresh rates that the device supports. To change the current refresh rate, call `IVariableRefreshRate.SetRefreshRateByIndex` with a valid index for the array of supported refresh rates.

**Note:** The supported refresh rates depend on the model of the phone, Android Display Settings, and application-specific settings in Samsung Game Launcher.

The Variable Refresh Rate API is supported on all devices where `UnityEngine.AdaptivePerformance.Samsung.Android.VariableRefreshRate.Instance` is not `null`.

If the current refresh rate or the list of supported refresh rate changes because of an external event, the `IVariableRefreshRate.RefreshRateChanged` event is triggered. This can happen when a user is making changes to the Display Settings.

The Unity core API `Screent.currentResolution.refreshRate` is automatically updated when the refresh rate changes. This update might not happen immediately, so it is not recommended to cache the value of `Screent.currentResolution.refreshRate` in your application.

## Device compatibility

For information on which devices that support Variable Refresh Rate supports, see [Requirements and compatibility](requirements.md#variable-refresh-rate).

## Project Settings

To enable proper timing for Adaptive Performance, you need to enable the **Frame Timing Stats** option (menu: **Edit** > **Project Settings** > **Player** > **Other Settings**).

If you want to use `Application.targetFrameRate` to limit the target frame rate, set the **VSync Count** option under **Edit** > **Project Settings** > **Quality** > **Other** to **Don't Sync**.

Unity has several quality levels in the quality settings. It's best practice to switch the **VSync Count** to **Don't Sync** for each quality level. This avoids issues with Adaptive Performance features like Adaptive Framerate and limiting the target framerate with `Application.targetFrameRate`.

### Optimized Frame Pacing

Adaptive Performance and Variable Refresh Rate are not compatible with frame pacing and it's best practice to disable **Optimized Frame Pacing** under **Edit** > **Project Settings** > **Player** > **Resolution and Presentation**.