DFS(4) | Device Drivers Manual (macppc) | DFS(4)

# 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), sysctl(8)

MPC7450 RISC Microprocessor Family Reference Manual.

# HISTORY

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

May 25, 2011 | Debian