Improve frequency scaling-related manual pages
[dragonfly.git] / share / man / man4 / est.4
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e9c04a6f 32.Dd October 10, 2014
03d5b052 33.Dt EST 4
fb5b3747 34.Os
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35.Sh NAME
36.Nm est
37.Nd Enhanced SpeedStep Technology support
38.Sh SYNOPSIS
39To compile this driver into the kernel, place the following line in your
40kernel configuration file:
41.Bd -ragged -offset indent
42.Cd "options CPU_ENABLE_EST"
43.Ed
44.Pp
45To load this driver as a module at boot time, place the following line in
46.Xr loader.conf 5 :
47.Bd -literal -offset indent
48est_load="YES"
49.Ed
50.Sh DESCRIPTION
51The
52.Nm
53driver provides support for the
54.Tn Enhanced SpeedStep Technology
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55present in some CPUs.
56Please note that
57.Xr powerd 8
58should be preferred if it is working properly on your system.
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59.Pp
60If the CPU is supported
61.Nm
62creates the following variables in the
63.Va machdep.est
64branch of the
65.Xr sysctl 3
66MIB.
67.Bl -tag -width ".Va frequency.available" -offset indent
68.It Va frequency.available
8e5e11bf 69The list of frequencies supported by
03d5b052 70.Nm
8e5e11bf 71for the CPU (read only).
03d5b052 72.It Va frequency.current
8e5e11bf 73The current CPU frequency (read only).
03d5b052 74.It Va frequency.target
8e5e11bf 75The target CPU frequency (read/write).
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76.El
77.Pp
78An associated userland daemon which is part of the
79.Xr pkgsrc 7
80collection
81.Pa ( sysutils/estd )
82can be used to dynamically set the CPU frequency depending on utilization.
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83.Sh SEE ALSO
84.Xr powernow 4 ,
85.Xr powerd 8
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86.Sh HISTORY
87The
88.Nm
89driver first appeared in
90.Dx 1.5 .