Legacy Documentation: Version 5.6 (Go to current version)
  • C#
  • JS

Script language

Select your preferred scripting language. All code snippets will be displayed in this language.


Suggest a change


Thank you for helping us improve the quality of Unity Documentation. Although we cannot accept all submissions, we do read each suggested change from our users and will make updates where applicable.


Submission failed

For some reason your suggested change could not be submitted. Please <a>try again</a> in a few minutes. And thank you for taking the time to help us improve the quality of Unity Documentation.



public static var backgroundLoadingPriority: ThreadPriority;
public static ThreadPriority backgroundLoadingPriority;


Priority of background loading thread.

Lets you control how long it takes to load data asynchronously vs performance impact on the game while loading in the background.

Asynchronous load functions that load objects (Resources.LoadAsync, AssetBundle.LoadAssetAsync, AssetBundle.LoadAllAssetAsync), scenes (Application.LoadLevelAsync, Application.LoadLevelAdditiveAsync) do data read and deserealization on a separate background loading thread and object integration on a main thread. Integration depends on an object type and for textures, meshes means uploading data to the GPU, audio clips prepare data for playing.

To avoid hiccups we limit integration time on a main thread depending on backgroundLoadingPriority value:
- ThreadPriority.Low - 2ms;
- ThreadPriority.BelowNormal - 4ms;
- ThreadPriority.Normal - 10ms;
- ThreadPriority.High - 50ms.
This is a maximum time all asynchronous operations can spend within a single frame on a main thread.

Background loading thread uses backgroundLoadingPriority directly.

    // Load as much data as possible, as a result frame rate will drop.
// Good for fast loading when showing progress bars.
Application.backgroundLoadingPriority = ThreadPriority.High;

// Load data very slowly and try not to affect performance of the game. // Good for loading in the background while the game is playing. Application.backgroundLoadingPriority = ThreadPriority.Low;
using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { void Example() { Application.backgroundLoadingPriority = ThreadPriority.High; Application.backgroundLoadingPriority = ThreadPriority.Low; } }