安装cpufrequtils：
yu@ubuntu:~$ sudo apt-get install cpufrequtils
查看cpu的信息：
yu@ubuntu:~$ sudo cpufreq-infocpufrequtils 007: cpufreq-info (C) Dominik Brodowski 2004-2009Report errors and bugs to cpufreq@vger.kernel.org, please.analyzing CPU 0: driver: acpi-cpufreq CPUs which run at the same hardware frequency: 0 CPUs which need to have their frequency coordinated by software: 0 maximum transition latency: 4294.55 ms. hardware limits: 800 MHz - 1.90 GHz available frequency steps: 1.90 GHz, 1.80 GHz, 1.60 GHz, 1.40 GHz, 1.20 GHz, 1000 MHz, 800 MHz available cpufreq governors: conservative, ondemand, userspace, powersave, performance current policy: frequency should be within 800 MHz and 1.90 GHz. The governor "ondemand" may decide which speed to use within this range. current CPU frequency is 800 MHz (asserted by call to hardware). cpufreq stats: 1.90 GHz:-nan%, 1.80 GHz:-nan%, 1.60 GHz:-nan%, 1.40 GHz:-nan%, 1.20 GHz:-nan%, 1000 MHz:-nan%, 800 MHz:-nan% (12092) analyzing CPU 1: driver: acpi-cpufreq CPUs which run at the same hardware frequency: 1 CPUs which need to have their frequency coordinated by software: 1 maximum transition latency: 4294.55 ms. hardware limits: 800 MHz - 1.90 GHz available frequency steps: 1.90 GHz, 1.80 GHz, 1.60 GHz, 1.40 GHz, 1.20 GHz, 1000 MHz, 800 MHz available cpufreq governors: conservative, ondemand, userspace, powersave, performance current policy: frequency should be within 800 MHz and 1.90 GHz. The governor "ondemand" may decide which speed to use within this range. current CPU frequency is 8http://i.cnblogs.com/EditPosts.aspx?opt=100 MHz (asserted by call to hardware). cpufreq stats: 1.90 GHz:-nan%, 1.80 GHz:-nan%, 1.60 GHz:-nan%, 1.40 GHz:-nan%, 1.20 GHz:-nan%, 1000 MHz:-nan%, 800 MHz:-nan% (13263)
从上面可以看到本机cpu的频率限制在800M～1.9GHZ之间。
可选设置频率有1.90GHz 1.80GHz 1.60GHz 1.40GHz 1.20GHz 1000MHz 800MHz
cpu对用的模式有5种：conservative, ondemand, userspace, powersave,performance
分别对应 自适应调节模式 自调节模式 用户（有root权限）自定义模式省电模式 最高或者最低频率
可参考：
设置cpu模式：sudo cpufreq-set -g {
conservative | ondemand | userspace | powersave | performance }设置cpu频率: sudo cpufreq-set -f {800~1900}(设置你的频率，使用cpufreq-info可以查看你的cpu支持哪些)
使用 cpufred-set -d 600M (最低) ，cpufreq-set -u 1.5G (最高)