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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.
51 Maximum mode chooses the highest performance values.
52 Minimum mode selects the lowest performance values to get the most power
54 Adaptive mode attempts to strike a balance by degrading performance when
55 the system appears idle and increasing it when the system is busy.
56 It offers a good balance between a small performance loss for greatly
57 increased power savings.
63 utility recognizes the following runtime options:
64 .Bl -tag -width ".Fl r Ar percent"
68 to use while on AC power.
72 to use while on battery power.
74 Specifies the CPU idle percent level when
76 mode should begin to degrade performance to save power.
77 The default is 90% or higher.
81 to use normally when the AC line state is unknown.
83 Specifies a different polling interval (in milliseconds) for AC line state
84 and system idle levels.
85 The default is 500 ms.
87 Specifies an alternative file in which the process ID should be stored.
89 .Pa /var/run/powerd.pid .
91 Specifies the CPU idle percent level where
93 mode should consider the CPU running and increase performance.
94 The default is 65% or lower.
97 Messages about power changes will be printed to stdout and
99 will operate in the foreground.
108 utility first appeared in
121 added features, and wrote this manual page.
125 utility should also power down idle disks and other components besides the CPU.
131 they may override each other.
136 should probably use the
138 interface instead of polling for AC line state.