---
title: groups
framework: metalperformanceshadersgraph
role: symbol
role_heading: Instance Property
path: metalperformanceshadersgraph/mpsgraphconvolution3dopdescriptor/groups
---

# groups

The number of partitions of the input and output channels.

## Declaration

```swift
var groups: Int { get set }
```

## Discussion

Discussion The convolution operation divides input and output channels in groups partitions. input channels in a group or partition are only connected to output channels in corresponding group. Number of weights the convolution needs is outputFeatureChannels x inputFeatureChannels/groups x kernelDepth x kernelWidth x kernelHeight