昨天高铁上拿T480切win10系统看电影，为了节电给细调了个省电策略（设置CPU性能30%），不知是不是因为这个原因，今天切回Ubuntu1604工作导致CPU工作频率非常低。
查阅了一下相关方法，cpufreq工具还是很好用的！
安装：sudo apt-get install cpufreq
显示当前CPU核心信息：cpufreq-info
然后会列出当前电脑的核心数及具体的信息，主要有下面几条：
analyzing CPU 0:
driver: intel_pstate
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: 400 MHz - 4.00 GHz 单核工作频率范围
available cpufreq governors: performance, powersave Ubuntu下两种不同的默认工作模式：性能/省电
current policy: frequency should be within 400 MHz and 4.00 GHz.
The governor "performance" may decide which speed to use
within this range.
current CPU frequency is 400 MHz.
设置CPU工作模式：
sudo cpufreq-set -g performance // 通电下当然进入性能模式
自定义CPU频率
sudo cpufreq-set -d 1800m -u 2700m // 适用模式：powersave|ondemand|conservative|performance
sudo cpufreq-set -f {1800m~2700m} // 适用模式：userspace