# T4200 CPU Frequency Scaling



## aaro (Jan 16, 2012)

I can't get my laptop Compaq CQ60-420US to scale the cpu frequency. I have followed the how-to from this forum but still no luck. I have checked that the frequency scales successfully in linux, the temperature there is 50 C idle. Also in linux the frequency scales are 1200, 1600 and 2000, very different from the ones indicated by the driver in FreeBSD. In my FreeBSD 7.4 install, the temperature stays in 54 C idle and the fan is always on at high speed (like a little vacuum). Any help appreciated.

*sysctl dev.est*

```
dev.est.0.%desc: Enhanced SpeedStep Frequency Control
dev.est.0.%driver: est
dev.est.0.%parent: cpu0
dev.est.0.freq_settings: 2000/35000
dev.est.1.%desc: Enhanced SpeedStep Frequency Control
dev.est.1.%driver: est
dev.est.1.%parent: cpu1
dev.est.1.freq_settings: 2000/35000
```
*sysctl dev.cpu*

```
dev.cpu.0.%desc: ACPI CPU
dev.cpu.0.%driver: cpu
dev.cpu.0.%location: handle=\_PR_.CPU0
dev.cpu.0.%pnpinfo: _HID=none _UID=0
dev.cpu.0.%parent: acpi0
dev.cpu.0.freq: 1250
dev.cpu.0.freq_levels: 2000/35000 1750/30625 1500/26250 1250/21875 1000/17500 750/13125 500/8750 250/4375
dev.cpu.0.cx_supported: C1/1 C2/1 C3/17
dev.cpu.0.cx_lowest: C1
dev.cpu.0.cx_usage: 100.00% 0.00% 0.00% last 500us
dev.cpu.1.%desc: ACPI CPU
dev.cpu.1.%driver: cpu
dev.cpu.1.%location: handle=\_PR_.CPU1
dev.cpu.1.%pnpinfo: _HID=none _UID=0
dev.cpu.1.%parent: acpi0
dev.cpu.1.cx_supported: C1/1 C2/1 C3/17
dev.cpu.1.cx_lowest: C1
dev.cpu.1.cx_usage: 100.00% 0.00% 0.00% last 500us
```
/etc/rc.conf

```
# -- sysinstall generated deltas -- # Sat Jan 14 08:58:11 2012
# Created: Sat Jan 14 08:58:11 2012
# Enable network daemons for user convenience.
# Please make all changes to this file, not to /etc/defaults/rc.conf.
# This file now contains just the overrides from /etc/defaults/rc.conf.
hostname="laptop-compaq"
ifconfig_ath0="WPA DHCP"
keymap="us.iso"
linux_enable="YES"
moused_enable="YES"
hald_enable="YES"
dbus_enable="YES"
powerd_enable="YES"
powerd_flags="-a adp -b adp -n adp -m 1200"
```
dmesg:View attachment freebsd-dmesg.txt


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## mav@ (Jan 16, 2012)

Looks like for some reason your ACPI BIOS exports only one CPU frequency. The rest of frequencies you see created by throttling, that is not very effective. You should try to use C-states to save power, but if you are using 7.4, it may be difficult. Read this: http://wiki.freebsd.org/TuningPowerConsumption to see whole picture.


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