1.\" $NetBSD: powernow.4,v 1.5 2020/11/14 20:04:46 wiz Exp $ 2.\" 3.\" Copyright (c) 2011 Jukka Ruohonen <jruohonen@iki.fi> 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Neither the name of the author nor the names of any 12.\" contributors may be used to endorse or promote products derived 13.\" from this software without specific prior written permission. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS 16.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 17.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 18.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 19.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25.\" POSSIBILITY OF SUCH DAMAGE. 26.\" 27.Dd September 7, 2020 28.Dt POWERNOW 4 x86 29.Os 30.Sh NAME 31.Nm powernow 32.Nd AMD PowerNow! and Cool'n'Quiet 33.Sh SYNOPSIS 34.Cd "powernow0 at cpu0" 35.Sh DESCRIPTION 36The 37.Nm 38driver supports 39.Tn AMD 40.Dq PowerNow! 41and 42.Dq Cool'n'Quiet 43.Tn CPU 44frequency scaling technologies. 45The following 46.Xr sysctl 8 47variables are available with 48.Nm : 49.Bl -tag -width "machdep.cpu.frequency.available" -offset 2n 50.It Ic machdep.cpu.frequency.target 51The target frequency of the 52.Tn CPUs . 53.It Ic machdep.cpu.frequency.current 54The current frequency. 55.It Ic machdep.cpu.frequency.available 56The available frequencies. 57.El 58.Pp 59Note, however, that these variables are 60not guaranteed to exist in the future versions of 61.Nx . 62.Sh SEE ALSO 63.Xr acpicpu 4 , 64.Xr x86/est 4 , 65.Xr x86/odcm 4 66.Sh CAVEATS 67The 68.Nm 69driver is considered a legacy interface to 70be used only with relatively old systems. 71The driver supports only 72.Tn AMD 73processor families 74.Tn K7 75(for instance, Duron, Athlon, and some Semprons) and 76.Tn K8 77(namely, the early 64-bit family, including Athlon 64, Opteron, and Turion). 78