---
title: peerIndex
framework: metal
role: symbol
role_heading: Instance Property
path: metal/mtldevice/peerindex
---

# peerIndex

The unique identifier for a GPU in a peer group.

## Declaration

```swift
var peerIndex: UInt32 { get }
```

## Discussion

Discussion If the GPU is part of a peer group (see peerGroupID or peerCount) the peer index is the GPU’s unique value within the group in the range [0, peerCount).

## See Also

### Identifying a GPU device

- [name](metal/mtldevice/name.md)
- [architecture](metal/mtldevice/architecture.md)
- [MTLArchitecture](metal/mtlarchitecture.md)
- [registryID](metal/mtldevice/registryid.md)
- [location](metal/mtldevice/location.md)
- [MTLDeviceLocation](metal/mtldevicelocation.md)
- [locationNumber](metal/mtldevice/locationnumber.md)
- [isLowPower](metal/mtldevice/islowpower.md)
- [isRemovable](metal/mtldevice/isremovable.md)
- [isHeadless](metal/mtldevice/isheadless.md)
- [peerGroupID](metal/mtldevice/peergroupid.md)
- [peerCount](metal/mtldevice/peercount.md)