ubuntu电源管理

CPU：英特尔 酷睿i3 双核  M 370  2.40GHz

核心显卡：Intel Corporation Core Processor Integrated Graphics Controller

独立显卡：NVIDIA Corporation GF108 [GeForce GT 425M]

主硬盘：西部数据 500GB 5400 转/分钟

操作系统： ubuntu 12.04LTS

1 显示器

显示器这块历来是耗电大户，但是很多时候，你不可能为了省电把屏幕调到很暗的程度。

毕竟我们拿电脑是来工作的，不是受虐的。所以，亮度调节这块，自己决定。而且ubuntu

12.04可以使用键盘热键调节，不需要配置就可以了。

2 CPU

我使用了cpufreq-info查看了CPU的情况，下面是我个人电脑上面CPU的数据：

cpufrequtils 007: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to [e-mail], please.

analyzing CPU 0:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1 2 3
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 10.0 us.
hardware limits: 933 MHz - 2.40 GHz
available frequency steps: 2.40 GHz, 2.27 GHz, 2.13 GHz, 2.00 GHz, 1.87 GHz, 1.73 GHz,
1.60 GHz, 1.47 GHz, 1.33 GHz, 1.20 GHz, 1.07 GHz, 933 MHz
available cpufreq governors: conservative, ondemand, userspace, powersave, performance
current policy: frequency should be within 933 MHz and 2.40 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 933 MHz (asserted by call to hardware).
cpufreq stats: 2.40 GHz:3.20%, 2.27 GHz:0.05%, 2.13 GHz:0.03%, 2.00 GHz:0.05%, 1.87 GHz:0.08%,
1.73 GHz:0.06%, 1.60 GHz:0.12%, 1.47 GHz:0.12%, 1.33 GHz:0.10%, 1.20 GHz:0.09%,
1.07 GHz:0.19%, 933 MHz:95.92% (1694)

analyzing CPU 1:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1 2 3
CPUs which need to have their frequency coordinated by software: 1
maximum transition latency: 10.0 us.
hardware limits: 933 MHz - 2.40 GHz
available frequency steps: 2.40 GHz, 2.27 GHz, 2.13 GHz, 2.00 GHz, 1.87 GHz, 1.73 GHz, 1.60 GHz,
1.47 GHz, 1.33 GHz, 1.20 GHz, 1.07 GHz, 933 MHz
available cpufreq governors: conservative, ondemand, userspace, powersave, performance
current policy: frequency should be within 933 MHz and 2.40 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 933 MHz (asserted by call to hardware).
cpufreq stats: 2.40 GHz:2.50%, 2.27 GHz:0.04%, 2.13 GHz:0.03%, 2.00 GHz:0.04%, 1.87 GHz:0.02%,
1.73 GHz:0.04%, 1.60 GHz:0.03%, 1.47 GHz:0.08%, 1.33 GHz:0.04%, 1.20 GHz:0.04%,
1.07 GHz:0.13%, 933 MHz:97.01% (1056)

analyzing CPU 2:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1 2 3
CPUs which need to have their frequency coordinated by software: 2
maximum transition latency: 10.0 us.
hardware limits: 933 MHz - 2.40 GHz
available frequency steps: 2.40 GHz, 2.27 GHz, 2.13 GHz, 2.00 GHz, 1.87 GHz, 1.73 GHz, 1.60 GHz,
1.47 GHz, 1.33 GHz, 1.20 GHz, 1.07 GHz, 933 MHz
available cpufreq governors: conservative, ondemand, userspace, powersave, performance
current policy: frequency should be within 933 MHz and 2.40 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 933 MHz (asserted by call to hardware).
cpufreq stats: 2.40 GHz:3.67%, 2.27 GHz:0.08%, 2.13 GHz:0.05%, 2.00 GHz:0.05%, 1.87 GHz:0.04%,
1.73 GHz:0.10%, 1.60 GHz:0.14%, 1.47 GHz:0.15%, 1.33 GHz:0.12%, 1.20 GHz:0.13%,
1.07 GHz:0.32%, 933 MHz:95.14% (1855)

analyzing CPU 3:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1 2 3
CPUs which need to have their frequency coordinated by software: 3
maximum transition latency: 10.0 us.
hardware limits: 933 MHz - 2.40 GHz
available frequency steps: 2.40 GHz, 2.27 GHz, 2.13 GHz, 2.00 GHz, 1.87 GHz, 1.73 GHz, 1.60 GHz,
1.47 GHz, 1.33 GHz, 1.20 GHz, 1.07 GHz, 933 MHz
available cpufreq governors: conservative, ondemand, userspace, powersave, performance
current policy: frequency should be within 933 MHz and 2.40 GHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 933 MHz (asserted by call to hardware).
cpufreq stats: 2.40 GHz:2.24%, 2.27 GHz:0.02%, 2.13 GHz:0.02%, 2.00 GHz:0.02%, 1.87 GHz:0.03%,
1.73 GHz:0.02%, 1.60 GHz:0.02%, 1.47 GHz:0.03%, 1.33 GHz:0.03%, 1.20 GHz:0.11%,
1.07 GHz:0.05%, 933 MHz:97.41% (795)

我们可以看到这个4核CPU的可用工作频率在933MHZ到2.40GHZ之间，而由cpufreq stats一块可以清楚的知道，4个CPU占97%左右的时候都是处在933MHZ的最低水平，所以，CPU频率这一块也不需要自动调节，它自动调节功能已经可以了。

3 显卡

使用lspci | grep VGA可以查看个人电脑上面的显卡类型，我的数据如下：

00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 18)

01:00.0 VGA compatible controller: NVIDIA Corporation GF108 [GeForce GT 425M] (rev ff)

从侦测数据上可以看到，我的电脑上面安装了核心显卡和N卡。

使用sudo cat /sys/kernel/debug/vgaswitcheroo/switch命令可以查看当前使用那一个

显卡，我的数据如下：

0:IGD:+:Pwr:0000:00:02.0

1:DIS: :Off:0000:01:00.0

其中第一行的IGD Pwr表示当前使用的是核心显卡（这是我配置之后的）。

一般情况下，ubuntu会默认使用独显，所以会非常耗电。这里最重要的一步就是关闭独显

，只使用核心显卡。下面的命令可以关闭独显：

echo IGD > /sys/kernel/debug/vgaswitcheroo/switch

echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

使用sudo cat /sys/kernel/debug/vgaswitcheroo/switch再次查看，如果出现如下数据

即表示关闭独显成功：

0:IGD:+:Pwr:0000:00:02.0

1:DIS: :Off:0000:01:00.0

在这里，如果要想开机时就关闭独显，可以在/etc/rc.local写入刚才命令即可。

4 硬盘

据说，ubuntu的电源管理有问题，对硬盘寿命有影响，我试了以下，貌似我的没什么影响。

使用如下命令可以查看：

sudo smartctl --all /dev/sda | grep 193

193 Load_Cycle_Count        0x0032   198   198   000    Old_age   Always       -       8199

如果最后那个数字(我的是8199)增长很快，你就得注意了，这个上限是60W次,超出之后硬

盘就报废了。

下面的脚本可以检测在10分钟时间它的增长速度：

smartctl --all /dev/sda | grep 193;sleep 600;smartctl --all /dev/sda | grep 193

看看你中彩没有，我觉得这个谣言的成分大一点。。。。