---
title: "supportsVertexAmplificationCount(_:)"
framework: metal
role: symbol
role_heading: Instance Method
path: "metal/mtldevice/supportsvertexamplificationcount(_:)"
---

# supportsVertexAmplificationCount(_:)

Returns a Boolean value that indicates whether the GPU supports an amplification factor.

## Declaration

```swift
func supportsVertexAmplificationCount(_ count: Int) -> Bool
```

## Parameters

- `count`: An integer that represents the number of output streams you want the GPU to generate from an input stream.

## Mentioned in

Improving rendering performance with vertex amplification

## Discussion

Discussion A vertex amplification factor of 1 has no effect because it effectively disables vertex amplification. important: Passing a vertex amplification factor of 1 or less to this method triggers an API validation error. For more information about vertex amplification, see Improving rendering performance with vertex amplification.

## See Also

### Checking render support

- [supportsRaytracing](metal/mtldevice/supportsraytracing.md)
- [supportsPrimitiveMotionBlur](metal/mtldevice/supportsprimitivemotionblur.md)
- [supportsRaytracingFromRender](metal/mtldevice/supportsraytracingfromrender.md)
- [supports32BitMSAA](metal/mtldevice/supports32bitmsaa.md)
- [supportsPullModelInterpolation](metal/mtldevice/supportspullmodelinterpolation.md)
- [supportsShaderBarycentricCoordinates](metal/mtldevice/supportsshaderbarycentriccoordinates.md)
- [areProgrammableSamplePositionsSupported](metal/mtldevice/areprogrammablesamplepositionssupported.md)
- [areRasterOrderGroupsSupported](metal/mtldevice/arerasterordergroupssupported.md)
- [areBarycentricCoordsSupported](metal/mtldevice/arebarycentriccoordssupported.md)