# StartSubsystem<T>()

> Start a subsystem instance of a given type. Subsystem is assumed to already be loaded from a previous call to CreateSubsystem.

## Definition

* **Type:** Method
* **Namespace:** [UnityEngine.AdaptivePerformance](/engine/6000.7/script-reference/unityengine/adaptiveperformance.md)
* **Assembly:** UnityEngine.AdaptivePerformanceModule

```csharp
protected void StartSubsystem<T>() where T : class, ISubsystem
```