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.Dd March 17, 2011
.Dt POWERNOW 4
.Os
.Sh NAME
.Nm powernow
.Nd PowerNow! Technology support
.Sh SYNOPSIS
To compile this driver into the kernel, place the following line in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "options CPU_ENABLE_POWERNOW"
.Ed
.Pp
To load this driver as a module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
powernow_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver provides support for the
.Tn PowerNow! Technology
present in AMD K8 CPUs.
.Pp
If the CPU is supported
.Nm
creates the following variables in the
.Va machdep.powernow
branch of the
.Xr sysctl 3
MIB.
.Bl -tag -width ".Va frequency.available" -offset indent
.It Va frequency.available
The list of frequencies supported by
.Nm
for the CPU (read only).
.It Va frequency.current
The current CPU frequency (read only).
.It Va frequency.target
The target CPU frequency (read/write).
.El
.Sh HISTORY
The
.Nm
driver first appeared in
.Dx 2.3 .