Why Is Linux Notebook Battery Life Still Poor? 907
Ganty writes "I recently purchased a Lenovo W500 notebook, and after 'downgrading' to XP and creating a dual partition, I found that I had a battery life of nearly three hours using the long-life battery, at this point I was a happy camper because it means that I can watch a DVD during a flight. I then tried various Linux distributions and found the battery life under FOS to be very disappointing, with an average of 45 minutes before a warning message. After settling on Ubuntu I then spent three days trying various hardware tweaks but I only managed to increase the battery life to one and a half hours. Unwanted services have been disabled, laptop mode has been enabled, the dual core CPU reduces speed when idle and the hard drive spins down when not needed. Obviously Apple with their X86 hardware and BSD based OS have got it right because the MacBooks last for hours, and a stock install of MS Windows XP gives me three hours of life. Why is battery life on notebooks so poor when using Linux? Some have suggested disabling various hardware items such as bluetooth and running the screen at half brightness but XP doesn't require me to do this and still gives a reasonable battery life."
Re:What about netbooks? (Score:5, Interesting)
On my Samsung NC10, Windows gives me about 6.5 to 7 hours of battery life, Ubuntu about 4.5 to 5.
Re:What about netbooks? (Score:5, Interesting)
I get 10 hours on winxp on my eeepc, and 7.5-ish on eeebuntu.
I'd love to know what to do to optimize eeebuntu more, since that's what I need for work.
Linux is not for laptops. (Score:2, Interesting)
Truth is: Linux is not specifically intended to have laptops as end target, think how bad is the experience with suspend/hibernate in Linux, look how horribly bad the wireless is supported (ok, also Intel's fault, but ever tried get the wireless up and running after your basic installation of many distributions?!). Then what to say of early laptops 'burning' with Linux? And lack of support for proper FAN regulation that makes them tenfolds noisy (ok, because the vendors exchanged their fan specs just with M$ sometimes), and so forth.
In general the FOSS community seems to me more oriented to "as long as is works" and "as long as is as powerful as possible" philosophy (ok, sometimes Power Saving rules are quite much odd, too). Serously, Linux has done many steps forward, but we're not (yet) ready for the desktop, on a laptop. Your mileage may vary depending on the distribution.
Re:power saving tip: disable the optical drive (Score:4, Interesting)
Re:What about netbooks? (Score:1, Interesting)
I had 6.5 to 7 hours when the battery was new, on Arch Linux with every useless thing off (Bluetooth/WLAN).
Didn't tweak much, but I think Ubuntu keeps everything on and anyhow, Ubuntu has alot of tasks running compared to Arch (like, 200 vs 20 if you ignore kernel threads.)
Re:Powertop (Score:2, Interesting)
Don't be an a-hole. There was a time when you too were ignorant about powertop.
Re:Powertop (Score:3, Interesting)
Yes, what kind of moron doesn't know about things that aren't installed?
Re:Do you have non anecdotal evidence? (Score:5, Interesting)
XP's default file system is NTFS, and NTFS is journaled, so I don't think Linux gets an easy out there...
Re:Do you have non anecdotal evidence? (Score:3, Interesting)
When it *is* the intended OS, it's usually a highly customized version/distribution that's optimized perfectly for the hardware, too. My Dell Mini 9, for example, gets about 5.5h of battery life with the Dell-branded Ubuntu installation. When I wiped it and installed another distro of my choice, the battery life dropped to 3h. While I loathe Ubuntu, I ended up going back to their Ubuntu installation because a netbook needs that kind of battery life.
Re:Poor choice for screensaver? (Score:4, Interesting)
Agreed. Simple web browser usage used to compare Linux and XP shows a 25% _increase_ in battery life under Linux. This was mostly doing research and reading emails. Flash sites tend to draw down the battery so I hold off on those until back on AC power. this was with a work issued laptop from Dell. I don't recall the model.
Buggy DSDT in BIOS (Score:5, Interesting)
You can fix a lot of these issues by following the instructions in one of the links below to decompile that portion of the BIOS, and recompile it using the Intel compiler. It isn't easy, and certainly isn't something an user should ever have to do. It did fix a lot of the power issues with my HP laptop though (Running hot, not booting on battery power unless a key was pressed, hibernation).
See
http://www.osnews.com/thread?230516 [osnews.com]
http://ubuntuforums.org/showthread.php?t=1036051 [ubuntuforums.org]
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/272247?comments=all [launchpad.net]
In this instance, you can blame MS's poor compiler for Linux's poor battery life.
Re:Powertop (Score:2, Interesting)
Another advice:
Use laptop_mode (http://samwel.tk/laptop_mode/)! It gives me additional hour on my 4 hour battery.
As one of the few (non-tech) lawyers..... (Score:5, Interesting)
power savings in Linux (Score:2, Interesting)
Lunatic4ever (Score:1, Interesting)
The only Linux distro that give me more battery life then Windows is Opensuse 11.1
Have you tried that one already?
Re:BIOS (Score:3, Interesting)
Really? I wondered why since most laptops have myriad settings in their BIOS for power management that they say to turn off BIOS power management when using software power management. I always wondered what exactly was the advantage of using software power management at all. I mean why not turn off software power management and use the BIOS settings exclusively? Are these 'microoptimizations' the reason?
Never seemed all that bad to me (Score:3, Interesting)
Just my own experience, but I've never seen differences in battery life that are this extreme. Linux has always been worse, but never more than about 10% on the laptops I've used, with one exception.
The only time I've seen a huge difference is on an HP laptop that I currently use as an SVN/Trac/CUPS server. The machine has a BIOS bug that prevents me from using ACPI in Linux, and HP never released a patch to fix it. The only way to keep the machine stable in Linux is to boot "acpi=off, noapic, nolapic". With no real power management, it drains mighty fast, even with all the hardware that gets disabled booting this way (webcam, wireless, etc).
On the other hand, a few years ago I owned a wonderful Sager laptop. With two double capacity batteries and a regular capacity battery, I could get a full 20 hours of battery life from the three (8 hours for double, 4 for regular) running Linux (Gentoo at the time), which was within 1 hour of the average total when I ran XP.
Linux does have worse battery life, for a number of reasons, but the difference doesn't seem significant on most hardware. It all seems to depend on hardware quirks in your machine.
Linux devices can get great battery life (Score:1, Interesting)
The device I work on has received industry recognition on its battery life and it runs Linux. But it's an ARM based handheld consumer electronics device. (I won't name names)
The tremendous amount of work our developers put into cutting every milliamp out of the system in the idle states is how we got the device so low. Out of the box on a random platform the energy saving features of Linux are non-existent. Add to this that on x86 systems there is a mess of different power savings interfaces and standards, some of them pretty badly implemented others just badly defined. You can tweak Linux in about two days to be power efficient on a particular laptop with a little know-how and a compiler. But your effort will be wasted on 90% of the other laptops out there. I blame this on Linus Torvalds for not recruiting a power expert to bring in and merge all the different patches necessary for good power savings on Linux. And on the immaturity of Linux's power infrastructure (doesn't exist). Providing only a primitive way for drivers, kernel subsystems, and userspace to communicate power needs.
You're wrong, plain and simple (Score:1, Interesting)
I have a Thinkpad W500 with the 2.8Ghz Dual Core and the 9 cell battery. I'm able to get more than 5 hours of battery life with linux. Watching a movie I'm still able to get more than 3 hours without any issues. If you would have gone to thinkwiki.org you would have found out that the W500 comes with switchable graphics. It comes with both a discreet ATI graphics card with 512MB and an integrated Intel GMA 4500HD. Probably you main culprit is the dual graphics. If you leave switchable graphics on and run the Intel driver, it will still have the ATI graphics chip running at full speed. If you just enable the ATI graphics and run anything but the FGLRX drivers, it will run the chip at full speed thus killing your battery life. Intel's GMA 4500HD is the best supported right now and it's what I run under Linux. Once you work out the the graphics issues, you should be in much better shape. The Intel GMA 4500HD is also under heavy development and you need to run the latest kernel. I roll my own from kernel.org.
Once you get your graphics sorted out, use powertop from there.
Also, Vista and Windows 7 can use the full extent of the W500. To roll back to XP is a step backwards. Yes, it needs more memory, so give it more memory.
Also, why even post this on Slashdot? If you would have done your home work, and posted in some thinkpad forums, you would have gotten this solved.
To say that Linux's power management is awful compared to XP or Windows Vista is just naive. I have had XP, Vista, and Windows 7 running on this laptop. And Linux gives me the best battery life.
Re:Well duh (Score:5, Interesting)
er, don't know about dead, and I wouldn't say "long live windows 7", but I will admit the battery power options are very impressive on Windows 7. Not only can you change the obvious like cpu speed, but you can go all the way down and adjust how long the CPU fan should be on if you're on battery, and it can change according to which battery profile you choose. It has more options than I've ever seen on any program, even more than NHC [pbus-167.com].
Re:power saving tip: disable the optical drive (Score:4, Interesting)
Re:power saving tip: disable the optical drive (Score:3, Interesting)
Not to mention the hassle of having to carry so many physical dvds around, a flash drive or hard disk is massively more convenient.
I get far more with Linux... (Score:4, Interesting)
Well, perhaps it's the distro? Or the hardware. On my Dell Vostro 1000 with a 6 cell battery, I get at absolute maximum 4 hours of battery live on WinXP. On a slightly stipped-down Mandriva Linux I've managed to squeeze 6 hours of use out of it while watching movies. Of course, you could say this isn't an _entirely_ fair test as I was running both the system and the movie from a USB flash drive, but considering I did nothing special in the installer, just told it to install to the flash drive, I'd say it's fair - if you could install Windows to flash that easily I'd run it from one too. Plus with my full version of Mandriva 2009.1 using KDE4 I still get at least as much battery life as I get on XP - and it actually last longer than XP does for gaming (specifically World of Warcraft).
Re:As one of the few (non-tech) lawyers..... (Score:3, Interesting)
Can anyone explain why my initial gut sense is an over-reaction?
Because you don't have sufficient grasp of the issues at hand. That's not meant as an insult. You could just as easily overwhelm me with lawyer-speak on a given lawyer-rific topic.
Should my replacement computer (another laptop) be Linux (other than Apple)?
There is no doubt that Linux will gain more visibility and users will know their computer runs a Linux distro. Linux is already 'everywhere' in lots of devices where the software is not visible to the end-user.
There is no doubt if you want to maximize control and distribution of your entertainment media going forward, Linux is the way to go. But running it on your laptop it depends on your level of interest.
At minimum, buy a Mac laptop, and don't run it as administrator. Then use the older tower you probably are replacing with the laptop and use it for serving media, backing up your mac, recording television at home and whatever else you need.
I'm ignoring the notion that you may have to run lawyer-related software. If so, you are probably constrained by the legal software.
Re:Poor choice for screensaver? (Score:3, Interesting)
Re:Poor choice for screensaver? (Score:3, Interesting)
Having recently installed Vista, 7, and Ubuntu on my laptop, I think Ubuntu was the most difficult. It asked things in unexpected ways and the timezone map was atrocious. I wouldn't say it was significantly more difficult but it was quite as easy as Vista or 7.
Re:Poor choice for screensaver? (Score:3, Interesting)
Yes, Linux not being as power efficient as other OSes doesn't have anything to do with Linus Torvalds thinking things like ACPI are "a complete design disaster in every way."
The ACPI specification is available to anyone [acpi.info].
Re:Poor choice for screensaver? (Score:3, Interesting)
Um Linux is a tickless kernel now?
Last I heard, the "tickless" kernel was more of a "tick less" kernel in that you could give it a clock divider to tick less often. So you could have it tick 100 times a second or 10 times a second instead of 1000 times a second as it does by default.
Of course, I have only encountered this in the realm of running VMs. You can get some pretty impressive clock skew under ESX with an older stock kernel and no tuning (hours a day)
-Steve
Re:Poor choice for screensaver? (Score:5, Interesting)
The last time I installed XP on my laptop I had lost some, but not all, of the OEM-supplied driver disks, and it ended up taking me a total of about eighteen hours of solid graft to get it to work. Incidentally, I grew up on Windows, and have only really gotten into FOSS stuff in the last three or four years, and the last time I installed Ubuntu (which took about twenty minutes) it had already configured my screen to the right resolution, got the wi-fi and bluetooth working, got the frickin' bog standard ethernet adapter working, and suggested that I might want to download the right drivers for my GPU by clicking OK and typing my password.
When people say these things, I always have to wonder whether they have ever actually installed Windows. Maybe it's just me, but it takes longer for XP or Vista to simply copy the base installation to the hard drives than it does for me to set up Ubuntu, and I still have to look up which packages I need to install to listen to MP3s or watch DVDs.
Re:Poor choice for screensaver? (Score:2, Interesting)
Re:Just one instance of a known problem... (Score:1, Interesting)
ATI have released some of their documentation (most of the baseline info about the R600/R700 chips). So they do deserve some kudos for that; they have released far more register information than Nvidia for example. As far as I know they haven't released all the info needed for really good powersaving, so maybe a little encouragement is required rather than chastisement. A good way to encourage them is to buy their hardware :) Personally all the graphics chipsets I have bought recently have been ATI, precisely because they have released far more information about recent chipsets than any other mainstream graphics chipset manufacturers.
Re:Just one instance of a known problem... (Score:3, Interesting)
Life's a compromise and if you aren't willing to compromise, you're going to miss out on things. Like battery life.
Re:Poor choice for screensaver? (Score:3, Interesting)
The last time I installed XP on my laptop I had lost some, but not all, of the OEM-supplied driver disks, and it ended up taking me a total of about eighteen hours of solid graft to get it to work. Incidentally, I grew up on Windows, and have only really gotten into FOSS stuff in the last three or four years, and the last time I installed Ubuntu (which took about twenty minutes) it had already configured my screen to the right resolution, got the wi-fi and bluetooth working, got the frickin' bog standard ethernet adapter working, and suggested that I might want to download the right drivers for my GPU by clicking OK and typing my password.
This is dead on! I tried to put XP on a laptop I found at the dumpster. Even after tracking down the drivers from the vendors website the bloody thing still didn't work right.
Pop in a Linux Mint disk and just like that I have a functional system. Sure, it has a few quirks (which I can't tell if it is the hardware or the software) but it's totally usable.
...and I still have to look up which packages I need to install to listen to MP3s or watch DVDs.
Try Linux Mint http://www.linuxmint.com/ [linuxmint.com] it's an Ubuntu variant that comes with a bunch of the proprietary stuff vanilla Ubuntu doesn't come with out of the box. It's pretty slick.
Re:Poor choice for screensaver? (Score:2, Interesting)
the Netbook remix does not in any way include a recompile of everything. It is not a port, it is just a few extra programs.
It consists of:
* 1 full screen application launcher
* a program called "maximiser" that makes windows open full screen with no decoration by default.
* A theme for gnome-panel
* A "go-home" panel applet that brings the launcher to the front
* A Window switcher applet that replaces the taskbar, and also provides an equivalent to the title bar of the currently focussed window.
* A preference to switch back to a regular gnome desktop.
At the moment, the netbook remix is purely about appearance. It works very well on desktop machines as well (particularly ones with lower resolution screens), and on earlier netbooks like the EEE 701 (with an Intel Celeron, not Atom)
You can install it on any Ubuntu machine simply by installing apt-get ubuntu-netbook-remix.
I am currently running it on my desktop machine at home - an Athlon 64 X2, which is not only not an Atom, not Intel, but is even 64 bit.
ACPI Sucks Life. Article is Much FUD. (Score:1, Interesting)
My battery life is great and better than I would get under XP. The root of the problem is ACPI, an intentional free software sabotage [slashdot.org] (link contains email from Bill Gates, quotes from Linus Torvalds and Intel engineers). XP has very poor power management and gnu/linux can only be worse on the worst of hardware where ACPI is not working at all and APM is not an option. The efficiency of gnu/linux, when it works, should be obvious from the choices Google and IBM make. These things can be obvious on gnu/linux desktops though programs like KPowerSave, which should tell you how well ACPI is working for you. It works for me. If it does not work for you, you now know why.
The next generation of ARM netbooks and tablets will be running GNU/Linux and they are going to have 10 hour battery life, aka better than your iPhone. The sooner makers drop ACPI and other poisoned specs for free software, the sooner we will all enjoy consistent and reliable computing.
Re:Missing The Point? (Score:2, Interesting)
You're comparing apples to oranges. The out-of-the-box-XP machine is being compared to a linux-put-on-a-windows-box machine.
If the original poster wanted a linux computer that has great optimizations out of the box, then maybe the original poster should have bought a laptop from system76.com or linuxcertified.com or something.