cpufrequtils可以根据不同的方案自动调节CPU的频率，从而达到在系统空闲时降低CPU温度、节省电力的目的。
Archlinux官方wiki已经介绍得很明白了：http://wiki.archlinux.org/index.php/Cpufrequtils_(简体中文)
使用后效果明显，CPU温度有所下降，下面是cpufrequtils在Arch上的工作情况：
[lenin@archer ~]$ cpufreq-info
cpufrequtils 007: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 10.0 us.
hardware limits: 800 MHz - 2.53 GHz
available frequency steps: 2.53 GHz, 2.53 GHz, 1.60 GHz, 800 MHz
available cpufreq governors: ondemand, performance
current policy: frequency should be within 800 MHz and 1.60 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 800 MHz.
analyzing CPU 1:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1
CPUs which need to have their frequency coordinated by software: 1
maximum transition latency: 10.0 us.
hardware limits: 800 MHz - 2.53 GHz
available frequency steps: 2.53 GHz, 2.53 GHz, 1.60 GHz, 800 MHz
available cpufreq governors: ondemand, performance
current policy: frequency should be within 800 MHz and 1.60 GHz.
The governor "performance" may decide which speed to use
within this range.
current CPU frequency is 1.60 GHz.