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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, adaptive and hiadaptive may be abbreviated
53 Maximum mode chooses the highest performance values.
54 Minimum mode selects the lowest performance values to get the most power
56 Adaptive mode attempts to strike a balance by degrading performance when
57 the system appears idle and increasing it when the system is busy.
58 It offers a good balance between a small performance loss for greatly
59 increased power savings.
60 Hiadaptive mode is alike adaptive mode, but tuned for systems where
61 performance and interactivity are more important then power consumption.
62 It rises frequency faster, drops slower and keeps twice lower CPU load.
63 The default mode is adaptive for battery power and hiadaptive for the rest.
67 utility recognizes the following runtime options:
68 .Bl -tag -width ".Fl r Ar percent"
72 to use while on AC power.
76 to use while on battery power.
78 Specifies the CPU load percent level when adaptive
79 mode should begin to degrade performance to save power.
80 The default is 50% or lower.
84 to use normally when the AC line state is unknown.
86 Specifies a different polling interval (in milliseconds) for AC line state
87 and system idle levels.
88 The default is 250 ms.
90 Specifies an alternative file in which the process ID should be stored.
92 .Pa /var/run/powerd.pid .
94 Specifies the CPU load percent level where adaptive
95 mode should consider the CPU running and increase performance.
96 The default is 75% or higher.
99 Messages about power changes will be printed to stdout and
101 will operate in the foreground.
110 utility first appeared in
123 added features, and wrote this manual page.
127 utility should also power down idle disks and other components besides the CPU.
133 they may override each other.
138 should probably use the
140 interface instead of polling for AC line state.