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32 .Nd "system power control utility"
46 utility monitors the system state and sets various power control options
48 It offers three modes (maximum, minimum, and adaptive) that can be
49 individually selected while on AC power or batteries.
50 The modes maximum, minimum, and adaptive may be abbreviated max, min, adp.
52 Maximum mode chooses the highest performance values.
53 Minimum mode selects the lowest performance values to get the most power
55 Adaptive mode attempts to strike a balance by degrading performance when
56 the system appears idle and increasing it when the system is busy.
57 It offers a good balance between a small performance loss for greatly
58 increased power savings.
64 utility recognizes the following runtime options:
65 .Bl -tag -width ".Fl r Ar percent"
69 to use while on AC power.
73 to use while on battery power.
75 Specifies the CPU idle percent level when
77 mode should begin to degrade performance to save power.
78 The default is 90% or higher.
82 to use normally when the AC line state is unknown.
84 Specifies a different polling interval (in milliseconds) for AC line state
85 and system idle levels.
86 The default is 500 ms.
88 Specifies an alternative file in which the process ID should be stored.
90 .Pa /var/run/powerd.pid .
92 Specifies the CPU idle percent level where
94 mode should consider the CPU running and increase performance.
95 The default is 65% or lower.
98 Messages about power changes will be printed to stdout and
100 will operate in the foreground.
109 utility first appeared in
122 added features, and wrote this manual page.
126 utility should also power down idle disks and other components besides the CPU.
132 they may override each other.
137 should probably use the
139 interface instead of polling for AC line state.