---
title: startOfEncoderSampleIndex
framework: metal
role: symbol
role_heading: Instance Property
path: metal/mtlblitpasssamplebufferattachmentdescriptor/startofencodersampleindex
---

# startOfEncoderSampleIndex

An index within a counter sample buffer that tells the GPU where to store counter data from the start of a blit pass.

## Declaration

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

## Mentioned in

Sampling GPU data into counter sample buffers

## Discussion

Discussion This property indicates where the GPU stores the counter data within an MTLCounterSampleBuffer instance that it samples at the beginning of a blit pass. You can tell the GPU to skip sampling at the start of the blit pass by assigning MTLCounterDontSample to this property. important: For MTLDevice instances that don’t support MTLCounterSamplingPoint.atStageBoundary (see supportsCounterSampling(_:)), set this property to MTLCounterDontSample.

## See Also

### Configuring the sample buffer attachment

- [sampleBuffer](metal/mtlblitpasssamplebufferattachmentdescriptor/samplebuffer.md)
- [endOfEncoderSampleIndex](metal/mtlblitpasssamplebufferattachmentdescriptor/endofencodersampleindex.md)