---
title: CVGetHostClockFrequency()
framework: corevideo
role: symbol
role_heading: Function
path: corevideo/cvgethostclockfrequency()
---

# CVGetHostClockFrequency()

Returns the frequency of updates to the system time.

## Declaration

```swift
func CVGetHostClockFrequency() -> Double
```

## Return Value

Return Value The current host frequency.

## Discussion

Discussion In macOS, the host time bases for Core Video and CoreAudio are identical—both are based on the mach_absolute_time function—so the values returned from either API can be used interchangeably.

## See Also

### Inspecting the Host Clock

- [CVGetCurrentHostTime()](corevideo/cvgetcurrenthosttime().md)
- [CVGetHostClockMinimumTimeDelta()](corevideo/cvgethostclockminimumtimedelta().md)