# DestroySystem(SystemHandle)

> Destroys one of the World's existing system instances.

## Definition

* **Type:** Method
* **Namespace:** [Unity.Entities](/engine/7000.0/script-reference/unity/entities.md)
* **Assembly:** UnityEngine.EntitiesModule

```csharp
public void DestroySystem(SystemHandle sysHandle)
```

### Parameters

**** (\[SystemHandle]\(/engine/7000.0/script-reference/unity/entities/systemhandle)): The system to destroy. Must be an existing instance in this World.

### Remarks

**Important:** This function creates a sync point, which means that the EntityManager waits for all currently running Jobs to complete before destroying the system, and no additional Jobs can start before the function is finished. A sync point can cause a drop in performance because the ECS framework may not be able to make use of the processing power of all available cores.