---
name: "dfs"
section: "4"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/dfs"
---

# dfs(4)

Dynamic Frequency Switching

## NAME

**dfs** – Dynamic Frequency Switching

## SYNOPSIS

**dfs\* at macgpio?**

## DESCRIPTION

The **dfs** driver provides support for the Dynamic Frequency Switching feature found on some PowerPC microprocessors.

It conserves power by lowering the processor operating frequency. Depending on the processor model, the processor-to-system bus ratio can be divided by two or four.

## HARDWARE

Processors supported by the **dfs** driver are part of the PowerPC G4 family and are found on various iBook and PowerBook machines:

```
MPC7447A	PowerPC 7447 "Apollo 7"
MPC7448		PowerPC 7448 "Apollo 8"
```

## SEE ALSO

[macgpio(4)](/macgpio/4.md), [sysctl(8)](/sysctl/8.md) *MPC7450 RISC Microprocessor Family Reference Manual*.

## HISTORY

Support for the **dfs** driver first appeared in OpenBSD 5.0.