---
title: kvImageUseFP16Accumulator
framework: accelerate
role: symbol
role_heading: Global Variable
path: accelerate/kvimageusefp16accumulator
---

# kvImageUseFP16Accumulator

A flag that specifies vImage uses faster but lower-precision internal arithmetic for floating-point 16-bit operations.

## Declaration

```swift
var kvImageUseFP16Accumulator: Int { get }
```

## Discussion

Discussion Pass this flag to floating-point 16-bit geometry and convolution functions to specify that vImage uses 16-bit floating-point arithmetic. Setting this flag improves performance by up to 2x but at the expense of a less precise result. The loss in precision is typically 2 or 3 bits. However, this may be different for some functions and kernels, and you should verify if a lower-precision arithmetic is suitable for your requirements.

## See Also

### Constants

- [vImage.Options](accelerate/vimage/options.md)
- [kvImageNoFlags](accelerate/kvimagenoflags.md)
- [kvImageLeaveAlphaUnchanged](accelerate/kvimageleavealphaunchanged.md)
- [kvImageDoNotTile](accelerate/kvimagedonottile.md)
- [kvImageHighQualityResampling](accelerate/kvimagehighqualityresampling.md)
- [kvImageGetTempBufferSize](accelerate/kvimagegettempbuffersize.md)
- [kvImagePrintDiagnosticsToConsole](accelerate/kvimageprintdiagnosticstoconsole.md)
- [kvImageNoAllocate](accelerate/kvimagenoallocate.md)
- [kvImageHDRContent](accelerate/kvimagehdrcontent.md)
- [kvImageDoNotClamp](accelerate/kvimagedonotclamp.md)