posted by Jimmy Oliver on Tue 16th Nov 2004 22:09 UTC

"SuSE and Laptops, Page 2/2"
Power Management

Linux laptop power management is my biggest pet peeve. If the same hardware gets only 1.5 hours of use under Linux and 4 hours under windows, there is a major problem. The issue is with ACPI support. With other distributions, I was unable to view battery status, scale my CPUs frequency, and blank my display when I shut the lid. This makes for a laptop that is pretty much unusable. Why settle for these deficiencies when you can just run Windows? Me, being the glutton for punishment that I am, settled for these problems because I felt that the added benefit and stability of Linux offset the cost of lost battery life. Now, I can have the best of both worlds.

SuSE's power management features, while far from perfect, are miles ahead of the curve. I can actually view how much battery life I have remaining! (Screenshot) When my battery gets too low, the system warns me to plug it in to avoid losing my work. While this seems like a small thing, it is revolutionary when you are used to obsessively saving every 2 seconds for fear of losing your work. My CPU even dynamically scales based on the current system load. (Screenshot) If I'm compiling code or generally taxing the processor, the frequency jumps up to 1.5GHZ or 100%. When I'm doing simple email writing, or web browsing, the CPU scales back to 600Mhz or 50%.

The laptop screen also blanks when I close the lid! I know that seems small, but the battery savings are tremendous. (Screenshot) Another trick that SuSE has added is the ability to change your power profile on the fly. There are several modes to choose from based on your preferences. Acoustic, Performance, Powersave, and presentation modes are handy preset profiles for power management attributes. Presentation mode for example will keep your laptop from cutting off the display after a given period of elapsed time.

Lets face it. Linux boots slow compared to Windows. Desktop Linux users muse that this is OK, since you can leave your system running for years on end without a reboot because of the stability advantag Linux holds over Windows. In a portable environment this is not true since the time between button press and working system is critical. While SuSE still boots as slow as any of the other leading distributions, it does have tremendous support for software suspend. (Screenshot) With suspend to disk, you can be up and running in a fraction of the normal boot time. This is advantageous for many reasons. If you can suspend your system to disk, you can save precious battery life. Whenever a break in the work flow is needed to stretch your legs or grab a snack, you can suspend your laptop without depleting your battery. Since suspend to disk writes the entire contents of your system's memory out to your swap partition, you computer is really off. No power is expended in this sleep state, and you can return to your exact work environment upon resumption from suspend. There is one downside to this option. Proprietary video drivers from NviDIA and ATI do not work with software suspend. This means that if you want 3D acceleration, you have to sacrifice software suspend support and vice versa. Since gaming on my laptop is not considered a high priority, this is one trade off I am willing to make.


Network portability is one dimension of the portable computer that is handled much more intelligently than power management. (Screenshot) The ability to change from one network profile to another is key when traveling between diverse network environments. Using SuSE's powerful profile manager SCPM (System configuration profile management), I can swap almost effortlessly between network configurations. I currently have only two profiles configured, home and school These are working without flaw. SCPM coupled with the kinternet connection tool makes for the seemless transfer from from network to network.

Wireless support has been much improved in this version of SuSE as well. There is now native support for my Intel 2200BG wireless card. I do however still have to use YAST to download the firmware for the card, since it is not licensed under the GPL. Bluetooth is handled without issue. I can easily transfer snapshots from my Sony Ericsson camera phone to my computer without any laborious configuration file manipulation. Bluetooth using blueZ is truly Plug and Play.


With all of the portability changes in SuSE 9.2, I have only been able to scratch the surface. One thing is clear; SuSE professional has undergone massive improvements for users of mobile hardware. With the exit of Redhat from the consumer Linux space, SuSE is poised to corner the market. This is good news since Novell has began advocating open source solutions and opening up code like Ximian connector. While my ACPI supported sleep states like suspend to RAM and standby are still inoperable, the suspend to disk functionality now brings SuSE to a more level playing field with regards to Windows mobile systems. Based on my informal battery drain tests, SuSE users can expect the identical battery life as compared to WindowsXP. This is a boon for mobile uses with Penium M chips. If you have a laptop and you want to run Linux, SuSE 9.2 professional is an excellent choice.

About the Author
Jimmy Oliver is 28 years old and lives with his wife and 3 children in Atlanta Georgia USA. He works full time as a network engineer for Comcast Corporation.
If you would like to see your thoughts or experiences with technology published, please consider writing an article for OSNews.
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  1. "SuSE and Laptops, Page 1/2"
  2. "SuSE and Laptops, Page 2/2"
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