We can control the CPU frequency with the cpufrequtils package. Installation is quite easy.
$ sudo aptitude install cpufrequtils
To check to see if it’s installed.
[06:41:32] xavi@debian: ~ $ lsmod | grep -i cpu acpi_cpufreq 6796 1 cpufreq_powersave 1856 0 cpufreq_stats 3776 0 cpufreq_ondemand 6476 1 freq_table 4224 3 acpi_cpufreq,cpufreq_stats,cpufreq_ondemand cpufreq_userspace 3172 0 cpufreq_conservative 5960 0 processor 32576 4 acpi_cpufreq,thermal [06:45:26] xavi@debian: ~ $
Now we check the CPU frequency.
[05:43:20] xavi@debian: ~ $ cat /proc/cpuinfo | grep -i hz model name : Intel(R) Core(TM)2 Duo CPU P8600 @ 2.40GHz cpu MHz : 800.000 model name : Intel(R) Core(TM)2 Duo CPU P8600 @ 2.40GHz cpu MHz : 800.000 [05:43:40] xavi@debian: ~ $
We see we have a CPU capable of running at 2.40GHz. Now lets check the speed at which is running now.
[05:43:40] xavi@debian: ~ $ cpufreq-info
cpufrequtils 004: cpufreq-info (C) Dominik Brodowski 2004-2006
Report errors and bugs to cpufreq@lists.linux.org.uk, please.
analyzing CPU 0:
driver: acpi-cpufreq
CPUs which need to switch frequency at the same time: 0 1
hardware limits: 800 MHz - 2.40 GHz
available frequency steps: 2.40 GHz, 2.40 GHz, 1.60 GHz, 800 MHz
available cpufreq governors: powersave, ondemand, userspace, conservative, performance
current policy: frequency should be within 800 MHz and 2.40 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 800 MHz.
cpufreq stats: 2.40 GHz:13,14%, 2.40 GHz:0,66%, 1.60 GHz:2,10%, 800 MHz:84,11% (30059)
analyzing CPU 1:
driver: acpi-cpufreq
CPUs which need to switch frequency at the same time: 0 1
hardware limits: 800 MHz - 2.40 GHz
available frequency steps: 2.40 GHz, 2.40 GHz, 1.60 GHz, 800 MHz
available cpufreq governors: powersave, ondemand, userspace, conservative, performance
current policy: frequency should be within 800 MHz and 2.40 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 800 MHz.
cpufreq stats: 2.40 GHz:13,14%, 2.40 GHz:0,66%, 1.60 GHz:2,10%, 800 MHz:84,11% (30059)
[05:44:56] xavi@debian: ~ $
We see is running most of the time at 800 MHz. Lets go ahead and increase the CPU speed.
[05:44:56] xavi@debian: ~ $ sudo cpufreq-set -c 1 -d 2401000 -u 2401000; echo $? [sudo] password for xavi: 0 [05:46:31] xavi@debian: ~ $
On the previous command -d selects the minimum speed and -u selects the maximum speed. Now lets check the new speed.
[05:47:00] xavi@debian: ~ $ cpufreq-info ; date
cpufrequtils 004: cpufreq-info (C) Dominik Brodowski 2004-2006
Report errors and bugs to cpufreq@lists.linux.org.uk, please.
analyzing CPU 0:
driver: acpi-cpufreq
CPUs which need to switch frequency at the same time: 0 1
hardware limits: 800 MHz - 2.40 GHz
available frequency steps: 2.40 GHz, 2.40 GHz, 1.60 GHz, 800 MHz
available cpufreq governors: powersave, ondemand, userspace, conservative, performance
current policy: frequency should be within 2.40 GHz and 2.40 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 2.40 GHz.
cpufreq stats: 2.40 GHz:13,28%, 2.40 GHz:0,65%, 1.60 GHz:2,09%, 800 MHz:83,98% (30177)
analyzing CPU 1:
driver: acpi-cpufreq
CPUs which need to switch frequency at the same time: 0 1
hardware limits: 800 MHz - 2.40 GHz
available frequency steps: 2.40 GHz, 2.40 GHz, 1.60 GHz, 800 MHz
available cpufreq governors: powersave, ondemand, userspace, conservative, performance
current policy: frequency should be within 2.40 GHz and 2.40 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 2.40 GHz.
cpufreq stats: 2.40 GHz:13,28%, 2.40 GHz:0,65%, 1.60 GHz:2,09%, 800 MHz:83,98% (30177)
Xov Set 2 05:47:14 EDT 2010
[05:47:14] xavi@debian: ~ $
We clearly see speed has been increased to 2.4 GHz which is the maximum speed this box of capable to work at.