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To continue on the topic of my previous post, I introduce you some tips under Linux (Ubuntu & Debian distributions) and general tips to increase your laptop’s battery life.

Turn off the screen

You have to make a phone call, go through a document or… a body need. During this time, you often leave your computer on. Rather than keeping your monitor on or suspending the system (note that when the system wakes up, it consumes a great amount of energy), why not turn the screen off temporary with a single click?

For this, you just have to create a launcher (shortcut) and configure it to execute this command:

xset dpms force off

Then, it can be added to your taskbar or desktop. For daily use, you can also assign it to your own keyboard shortcut.

The acronym DPMS stands for Display Power Management Signaling. It is a command line program that allows power saving behaviour of monitors when the computer is not in use. Other options are available. You can read this post for more information.

CPU Scaling

CPU Scaling is a feature built into most modern mobile CPUs that allows them to scale up or down in how fast they run (the frequency). If you have a fairly modern mobile computer there is a very good chance that your CPU can handle frequency scaling. For example, my five-year-old computer is based on an Intel Centrino CPU which supports it !

It is a pity that your processor runs at full speed if you are using a word processing or surfing the internet. Unless you are editing a movie or playing video games, this enables you to extend the use time of your laptop.

The idea is to “underclock” the processor when it is not fully stressed by your applications. A processor can save energy by running slower. Unfortunately, this will result in a slight performance degradation. So you have to find the good compromise.

Processors handle scaling differently. Various frequencies and modes are available depending on your model. To know yours, you need to install and activate the “CPU Frequency Scaling Monitor” applet.

Here is a short explanation for each mode:

• “Powersave” will keep the CPU constantly at the lowest frequency. This mode is very useful to preserve the battery;
• “Ondemand” will set the CPU at the lowest frequency until use of the CPU increases, then it will automatically set it up to the highest frequency. This is generally the default mode;
• “Performance” simply sets the CPU at the highest available frequency. It is better to have your laptop plugged-in while using this mode;
• “Conservative” is quite similar to the « Ondemand » mode. Your CPU will go up as needed, starting at the lowest frequency, and then setting up to the next available frequency (not the highest). It is the best compromise when you do not pay too much attention to your battery;
• Finally, you also have the possibility of setting manually the frequency. In my case, I have four choices (0.798 GHz, 1.06 GHz, 1.33 GHz and 1.73 GHz).

GPU Scaling

The graphics card is also very energy-consuming. Following the example of the CPU, it is possible to put its chip into a low voltage mode. In my example, I use an ATI graphics card. It does seem that Nvidia provides a similar software.

We will use the command line tool “ATI Powerstate” available when you install the official driver. In the same time, we will make it more user-friendly for daily usage by adding a GUI.

First, you need to write a bash script:

#!/bin/bash

## Mode selection
    ACT=$(aticonfig --lsp | grep :  | zenity --list --title 'ATI PowerState' --width=230 --height=166 \
        --text='Select a mode :'\
        --column='Mode'\
);
        if [ '${PIPESTATUS[0]}' != '0' ]; then
            exit
        fi


## Available modes

    # Idle
        echo '$ACT' | grep '1:' >/dev/null
            if [ '$?' = 0 ] ; then
                aticonfig --set-powerstate=1 | echo message:Idle mode activated | zenity --notification --listen --window-icon='info'
            fi

    # Default
        echo '$ACT' | grep '2:' >/dev/null
            if [ '$?' = 0 ] ; then
                aticonfig --set-powerstate=2 | echo message:Normal mode activated | zenity --notification --listen --window-icon='info'
            fi

Then, we create a launcher to execute this script.

In my case, I have two power states available. You can have more choices depending on the model of your graphic chip. Thus, it can be necessary to modify the script. By default (whether the laptop is plugged-in or not), the graphic card will run at full speed.

After selection, a tooltip shows up to confirm you about the running mode.

Once again, you will be in a dilemma, choosing between energy saving and a decrease in performance. For example, the greatest 3D effects are a little bit jerky when I activate the idle mode.

Still and always the good practices…

Except these few tips which have required the installation and/or the use of specific software, there are no secrets to preserve the energy of your battery ! There are still the good practices, the ones that have always been known to work on any computer and under any operating system. Here is a non-exhaustive list:

• Disconnect your external devices when you do not use them: hard drive, USB stick, mouse, webcam or any USB powered device;
• Deactivate wireless technologies (WI-FI and Bluetooth) when you do not use it;
• Close the applications you do not use. Multitasking stresses the CPU and storing lot of information in memory consumes energy;
• Deactivate the extra and unnecessary 3D effects (Oh no ! My nice-looking visual effects ! I’m afraid that’s another compromise again…);
• Decrease the screen brightness if necessary;
• Under Windows, defragment your hard drive regularly. Of course, do not launch the defrag process while your laptop is not plugged-in;
• Finally (with no ulterior motive), keep in mind that some available operating systems manage defragmentation and battery lifetime better than others.

With all these advices, you will certainly succeed in double your battery lifetime, and thereby extend your battery lifespan.

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Let’s go a step back in time, a decade ago. And remember, (perhaps!) you were walking in the IT department of a major computer retailer. The laptops section was rather cramped compared to that of desktop computers. There were maybe two or three models at the most that would cost you a fortune for low performance.

But times are changing. Now, the IT department is full of laptops, netbooks, media tablets and other latest fashion technology. From now on, the desktop computers section is limited to a few models which are mainly designed for hardcore gamers… At the same time, the difference between a cellphone and a computer is vanishing. To phone is the primary function and becomes also the only difference.

Workplace is not lagging behind. For instance, it is common for companies to provide laptops to their employees.

Is this only a fad? This is certainly the case for some people but, generally speaking, mobile computing has become essential in our society. Computer hardware is constantly evolving to become ever more efficient and miniaturized. The software and hardware frontiers are constantly pushed back. For example, majority of cellphones now have touch screens and 3D television is finally coming to our homes. All things considered, the movie “Minority Report” directed by Steven Spielberg is not so far from reality (apart from the precognition of course).

More recently, “iPad” release has been one of the most important events worldwide this month. Apple succeeds in making an incredible marketing ploy based on innovation, keystone to its success. Endless queues, shortages, camping out (some people did not hesitate to pitch their tents outside of the famous “Apple Stores”, in order to be one of the first to reach the “holy grail”). The world is really turning upside down.

But there is still the flipside of the coin! Thus, a permanent internet connection, a high resolution touch screen and so on are very energy-consuming. Unfortunately, this in one major area where technology is not ready yet. Indeed, lithium batteries which are used in electronic devices in a long time seem to be outdated.

The battery is one of the most important component in the device but is also its biggest weakness. Thus, it is necessary to plug in the mobile device to charge its battery. In the worst case, you need to charge the battery once a day because your device consumes too much power. When you think about it, you realize that it goes against the main device’s feature which is to bring it with you everywhere without restraint.

On the other hand, some major manufacturers make unexpected and drastic decisions. When the battery is deficient, they choose to replace the whole product, rather than by fixing or replacing the battery. That raises the environmental issue, that has been discussed over the past few years and concerns all of us. It should be noted that the technology has become disposable. This situation is quite alarming, and especially sad when we know that this how we stimulate our economy…