# Linux Cpufrequtils CPU頻率控制

<p class="callout info">使用cpufrequtils可降頻來降低溫度和省電</p>

#### **確認CPU驅動**  


```
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_driver
```

**如果顯示為 `intel_pstate`，您可能需要禁用它並切換到 `intel-cpufreq` 驅動程序**

**編輯`/etc/default/grub`，在GRUB\_CMDLINE\_LINUX\_DEFAULT加入intel\_pstate=disable**

```
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash intel_pstate=disable"

update-grub
reboot
```

**再次確認狀態為`intel-cpufre`**

```
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_driver
```

#### **安裝Cpufrequtils**

```
apt-get install cpufrequtils
```

**查看支持cpu管理模式**

```
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
conservative ondemand userspace powersave performance schedutil
```

**查看CPU訊息**

```
cpufreq-info
```

```
root@pve:~# cpufreq-info
cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
  driver: intel_cpufreq
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 20.0 us.
  hardware limits: 1.20 GHz - 3.50 GHz
  available cpufreq governors: conservative, ondemand, userspace, powersave, performance, schedutil
  current policy: frequency should be within 1.20 GHz and 3.50 GHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 3.05 GHz.
```

**修改模式**

**編輯`/etc/init.d/cpufrequtils`**

```
ENABLE="true"
GOVERNOR="powersave"     <<<修改模式 ondemand改powersave
MAX_SPEED="0"
MIN_SPEED="0"
```

```
systemctl daemon-reload
/etc/init.d/cpufrequtils restart
```

```
root@pve:~# cpufreq-info
cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
  driver: intel_cpufreq
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 20.0 us.
  hardware limits: 1.20 GHz - 3.50 GHz
  available cpufreq governors: conservative, ondemand, userspace, powersave, performance, schedutil
  current policy: frequency should be within 1.20 GHz and 3.50 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency is 1.20 GHz.
```