我刚刚注意到我的笔记本电脑运行速度明显变慢了。我使用的是更新后的 13.04，但这个问题并不是在升级后立即出现的。在追踪问题后，我注意到两个处理器都以 800 MHz 运行，而不是最高 1800 MHz。无论负载如何，频率都保持在 800。以下是一些统计数据：
$ cpufreq-info
cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to [email protected], please.
analyzing CPU 0:
driver: powernow-k8
CPUs which run at the same hardware frequency: 0 1
CPUs which need to have their frequency coordinated by software: 0 1
maximum transition latency: 109 us.
hardware limits: 800 MHz - 1.80 GHz
available frequency steps: 1.80 GHz, 1.60 GHz, 800 MHz
available cpufreq governors: conservative, ondemand, userspace, powersave, performance
current policy: frequency should be within 800 MHz and 800 MHz.
The governor "performance" may decide which speed to use
within this range.
current CPU frequency is 800 MHz.
cpufreq stats: 1.80 GHz:0.00%, 1.60 GHz:0.00%, 800 MHz:100.00%
analyzing CPU 1:
driver: powernow-k8
CPUs which run at the same hardware frequency: 0 1
CPUs which need to have their frequency coordinated by software: 0 1
maximum transition latency: 109 us.
hardware limits: 800 MHz - 1.80 GHz
available frequency steps: 1.80 GHz, 1.60 GHz, 800 MHz
available cpufreq governors: conservative, ondemand, userspace, powersave, performance
current policy: frequency should be within 800 MHz and 800 MHz.
The governor "performance" may decide which speed to use
within this range.
current CPU frequency is 800 MHz.
cpufreq stats: 1.80 GHz:0.00%, 1.60 GHz:0.00%, 800 MHz:100.00%
请注意，“当前策略”表示频率在 800 到 800 之间，与硬件限制无关。原始调节器是“按需”，因此我将其更改为“性能”，以查看这是否会产生影响，但事实并非如此。无论调用多少次 cpufreq-set 或 cpufreq-selector 都不会改变频率。
环顾四周，我发现过去有几个人报告过类似的问题，尽管没有令人满意的答案。任何帮助都将不胜感激。
答案1
首先确保你连接的是优质交流电源。我的机器插在一根很长的延长线上，这就是问题的一部分。
接下来，假设 Bios 妨碍了操作，请尝试以下操作：
编辑 /etc/default/grub
将processor.ignore_ppc=1添加到GRUB_CMDLINE_LINUX_DEFAULT行。
运行 sudo update-grub
重新启动计算机。
这是来自http://www.woolie.co.uk/article/dell-laptop-stuck-800mhz-linux-fix/