1 .\" Copyright (c) 2005 Nate Lawson
2 .\" All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
7 .\" 1. Redistributions of source code must retain the above copyright
8 .\" notice, this list of conditions and the following disclaimer.
9 .\" 2. Redistributions in binary form must reproduce the above copyright
10 .\" notice, this list of conditions and the following disclaimer in the
11 .\" documentation and/or other materials provided with the distribution.
13 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 .Nd system power control utility
45 utility monitors the system state and sets various power control options
47 It offers three modes (max, min, and adaptive) that can be
48 individually selected while on AC power or batteries.
50 Maximum mode chooses the highest performance values.
51 Minimum mode selects the lowest performance values to get the most power
53 Adaptive mode attempts to strike a balance by degrading performance when
54 the system appears idle and increasing it when the system is busy.
55 It offers a good balance between a small performance loss for greatly
56 increased power savings.
62 utility recognizes the following runtime options:
63 .Bl -tag -width -i_percent
67 to use while on AC power.
71 to use while on battery power.
73 Specifies the CPU idle percent level when
75 mode should begin to degrade performance to save power.
76 The default is 90% or higher.
80 to use normally when the AC line state is unknown.
82 Specifies a different polling interval (in milliseconds) for AC line state
83 and system idle levels.
84 The default is 500 ms.
86 Specifies the CPU idle percent level where
88 mode should consider the CPU running and increase performance.
89 The default is 65% or lower.
92 Messages about power changes will be printed to stdout and
94 will operate in the foreground.
103 utility first appeared in
115 added features, and wrote this manual page.
119 utility should also power down idle disks and other components besides the CPU.
123 is used with power_profile, they may override each other.
126 should probably use the
128 interface instead of polling for AC line state.