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# kAudioSessionProperty_PreferredHardwareIOBufferDuration

Your preferred hardware I/O buffer duration in seconds. Do not set this property unless you require lower I/O latency than is provided by default.

```
var kAudioSessionProperty_PreferredHardwareIOBufferDuration: Int { get }
```

## Discussion

A read/write `Float32` value.

The actual I/O buffer duration may be different from the value that you request, and can be obtained from the [`kAudioSessionProperty_CurrentHardwareIOBufferDuration`](/documentation/AudioToolbox/kAudioSessionProperty_CurrentHardwareIOBufferDuration) property.

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