1.\" (c) Copyright 2010 by Matthew Dillon and Dima Ruban. Permission to 2.\" use and distribute based on the DragonFly copyright. 3.\" 4.Dd October 28, 2014 5.Dt POWERD 8 6.Os 7.Sh NAME 8.Nm powerd 9.Nd simple ACPI based CPU/power control 10.Sh SYNOPSIS 11.Nm 12.Op Fl dt 13.Op Fl p Ar hysteresis 14.Op Fl u Ar trigger_up 15.Op Fl r Ar poll_time 16.Op Fl T Ar sample_time 17.Sh DESCRIPTION 18The 19.Nm 20daemon monitors the CPU load and automatically adjusts the CPU 21frequency up or down. 22.Pp 23All CPUs will be set to their maximum frequency when the 1 second 24machine load exceeds 25% of one CPU. 25All CPUs will be set to their 26minimum frequency when the 10 second machine load drops below 12% of 27one CPU. 28.Pp 29The options are as follows: 30.Bl -tag -width ".Fl p Ar hysteresis" 31.It Fl d 32Debug option. 33Causes 34.Nm 35to not go to the background and prints some debug output to 36.Va stdout . 37.It Fl p Ar hysteresis 38Percent of the upper limit to subtract as an hysteresis value to scale 39down to the min frequency. 40The default is 10 (meaning 10%). 41.It Fl t 42Turbo mode. 43Disables switching to turbo mode as maximum frequency completely. 44Switching to turbo mode as maximum frequency is enabled by default, 45if the CPU supports it. 46.It Fl u Ar trigger_up 47Per CPU load limit in percent to force maximum frequency. 48The default is 25 (meaning an instantanious load of 0.25 on a 49single cpu). The load is calculated over 3 polls. 50It is suggested that this value not be made lower than 51around 7. 52.It Fl r Ar poll_time 53Polling time in seconds. Default is 1.0. 54Setting this value lower will poll for load changes faster. 55For example, a workstation might want to use 0.2 or 0.4. 56.Nm can become unstable if you make this value too small. 57.It Fl T Ar sample_time 58Total sample interval in seconds. Default is 8.0. 59This effects how quickly powerd ratchets down the frequency 60and cpus on an idle machine. Longer times will ratchet down 61more slowly. 62For example, a workstation might want to use a value of 30.0. 63.El 64.Sh EXAMPLES 65The defaults work well for servers but a workstation user might want 66to use something like the following in their 67.Pa /etc/rc.conf 68to ratchet up the machine more quickly in response to spike loads 69(such as when you are browsing). 70.Pp 71.Li powerd_enable="YES" 72.Pp 73.Li powerd_flags="-u 7 -r 0.2 -T 60" 74.Sh DIAGNOSTICS 75The 76.Nm 77utility will exit with a non-zero code if the required sysctls are not 78present. 79.Sh SEE ALSO 80.Xr acpi 4 , 81.Xr est 4 , 82.Xr powernow 4 83.Sh HISTORY 84The 85.Nm 86command first appeared in 87.Dx 2.7 . 88.Sh BUGS 89I'm shocked I tell you, shocked that there might be bugs in this program! 90