# SetMaximumPreMappedBufferCounts(int, int)

> Limits the amount of graphics memory Unity reserves for efficient rendering of Particle Systems.

## Definition

* **Type:** Method
* **Namespace:** [UnityEngine](/engine/6000.3/script-reference/unityengine.md)
* **Assembly:** UnityEngine.ParticleSystemModule

```csharp
public static void SetMaximumPreMappedBufferCounts(int vertexBuffersCount, int indexBuffersCount)
```

### Parameters

**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): The maximum number of cached vertex buffers.**** (\[int]\(https\://learn.microsoft.com/dotnet/api/system.int32)): The maximum number of cached index buffers.

### Remarks

To efficiently write particle data into graphics memory, Unity uses a pool of pre-allocated vertex buffers. When rendering a large number of particles, this pool will increase in size. If the number of particles decreases later, the pool still maintains this size.

Maintaining a large pool can make future rendering more efficient, in situations where a large number of particles are being rendered, and the pool is already pre-sized appropriately. However, a large pool uses more memory, so this function allows you to set a limit on the number of buffers in the cache.

If the total number of visible particles reaches the limit, Unity allocates new buffers and releases them on-demand within the frames that need them, rather than saving them for re-use on multiple frames. This can be slower but prevents the cache from using too much memory.

Modern graphics APIs, such as DirectX12, Vulkan and Metal, do not use a pre-allocated pool of vertex buffers, because they can operate efficiently without it. This method does nothing on these devices.