# Introduction to Variable Frame Rates Nowadays, low-temperature polycrystalline oxide (LTPO) screens are widely used. This type of screen supports switching between frame rates at multiple levels. For fast-changing content, such as shooting games and interactive animations, a high frame rate is required. It ensures smooth images while causing a high power consumption. For slow-changing content, such as game halls and clock update animations, a low frame rate is used. It consumes less power and does not cause frame freezing. The variable frame rate capability enables you to achieve a balance between performance experience and power consumption on devices with the LTPO screens. OpenHarmony supports this capability. You can use the variable frame rate APIs to develop related services. ## Use Scenarios The variable frame rate capability allows you to specify the frame rate in different scenarios. Typical use scenarios are as follows: - Configure the frame rate parameter for property animations or explicit animations. For details, see [Requesting Frame Rates for Animations](displaysync-animation.md). - Request an independent frame rate for UI components. For details, see [Requesting Frame Rates for UI Components](displaysync-ui.md). - Request an independent frame rate for custom content (such as gaming) through the **XComponent** on the native side. For details, see [Requesting Frame Rates for Custom Content](displaysync-xcomponent.md). - Request an independent frame rate for drawing of non-UI threads through NativeVsync on the native side. For details, see [NativeDisplaySoloist Development (C/C++)](displaysoloist-native-guidelines.md). ## Working Principles The variable frame rate provides the basic frame rate configuration for animation components, **XComponent**, and UI components. After a valid expected frame rate is set, the system collects the configured frame rate and divides the frequency on the rendering pipeline. ## Constraints The actual frame rate may be different from the expected one configured. It is limited by the system capability and screen refresh rate.