夏天来了，给电脑降温从CPU降频做起

在下使用的是Fedora 16，使用的计算机是IBM T400，今天手摸了下键盘发现烫手，用sensors查看了下温度53度左右，还是挺热的。于是决定查看下CPU的在用频率，如果频率很高，准备调下去点。

安装软件包 cpufrequtils

使用命令 yum install cpufrequtils

安装好后使用cpupower命令对cpu频率进行查看或设置：

Usage:    cpupower [-d|--debug] [-c|--cpu cpulist ] <command> [<args>]
Supported commands are:
    frequency-info
    frequency-set
    idle-info
    set
    info
    monitor
    help

（演示过程是频率由低往高调，降频时查看频率可调整范围。本范例仅供参考）
查看：

[root@localhost tiger506]# cpupower -c 0,1 frequency-info
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 - 2.40 GHz
  available frequency steps: 2.40 GHz, 2.40 GHz, 1.60 GHz, 800 MHz
  available cpufreq governors: conservative, userspace, powersave, ondemand, performance
  current policy: frequency should be within 800 MHz and 2.40 GHz.
                  The governor "userspace" may decide which speed to use
                  within this range.
  current CPU frequency is 1.60 GHz (asserted by call to hardware).
  boost state support:
    Supported: yes
    Active: yes
    25500 MHz max turbo 4 active cores
    25500 MHz max turbo 3 active cores
    25500 MHz max turbo 2 active cores
    25500 MHz max turbo 1 active cores
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 - 2.40 GHz
  available frequency steps: 2.40 GHz, 2.40 GHz, 1.60 GHz, 800 MHz
  available cpufreq governors: conservative, userspace, powersave, ondemand, performance
  current policy: frequency should be within 800 MHz and 2.40 GHz.
                  The governor "userspace" may decide which speed to use
                  within this range.
  current CPU frequency is 1.60 GHz (asserted by call to hardware).
  boost state support:
    Supported: yes
    Active: yes
    25500 MHz max turbo 4 active cores
    25500 MHz max turbo 3 active cores
    25500 MHz max turbo 2 active cores
    25500 MHz max turbo 1 active cores
设置：

[root@localhost tiger506]# cpupower -c 0,1 frequency-set -f 2.4G
Setting cpu: 0
Setting cpu: 1

查看结果：

[root@localhost tiger506]# cpupower -c 0,1 frequency-info
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 - 2.40 GHz
  available frequency steps: 2.40 GHz, 2.40 GHz, 1.60 GHz, 800 MHz
  available cpufreq governors: conservative, userspace, powersave, ondemand, performance
  current policy: frequency should be within 800 MHz and 2.40 GHz.
                  The governor "userspace" may decide which speed to use
                  within this range.
  current CPU frequency is 2.40 GHz (asserted by call to hardware).
  boost state support:
    Supported: yes
    Active: yes
    25500 MHz max turbo 4 active cores
    25500 MHz max turbo 3 active cores
    25500 MHz max turbo 2 active cores
    25500 MHz max turbo 1 active cores
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 - 2.40 GHz
  available frequency steps: 2.40 GHz, 2.40 GHz, 1.60 GHz, 800 MHz
  available cpufreq governors: conservative, userspace, powersave, ondemand, performance
  current policy: frequency should be within 800 MHz and 2.40 GHz.
                  The governor "userspace" may decide which speed to use
                  within this range.
  current CPU frequency is 2.40 GHz (asserted by call to hardware).
  boost state support:
    Supported: yes
    Active: yes
    25500 MHz max turbo 4 active cores
    25500 MHz max turbo 3 active cores
    25500 MHz max turbo 2 active cores
    25500 MHz max turbo 1 active cores
查看温度：

[root@localhost tiger506]# sensors
acpitz-virtual-0
Adapter: Virtual device
temp1:        +58.0°C  (crit = +127.0°C)
temp2:        +56.0°C  (crit = +100.0°C)

thinkpad-isa-0000
Adapter: ISA adapter
fan1:        2967 RPM
temp1:        +58.0°C 
temp2:        +54.0°C 
temp3:        +38.0°C 
temp4:        +72.0°C 
temp5:        +36.0°C 
temp6:            N/A 
temp7:        +36.0°C 
temp8:            N/A 
temp9:        +42.0°C 
temp10:       +53.0°C 
temp11:       +47.0°C 
temp12:           N/A 
temp13:           N/A 
temp14:           N/A 
temp15:           N/A 
temp16:           N/A 

coretemp-isa-0000
Adapter: ISA adapter
Core 0:       +56.0°C  (high = +105.0°C, crit = +105.0°C)
Core 1:       +54.0°C  (high = +105.0°C, crit = +105.0°C)