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Getting Better Battery Life w/ Linux?
Nuclear Elephant asks: "After a little hacking, Linux has been running great on my Thinkpad T30 for about a year now. I can talk to my cellphone and bluetooth devices, do all kinds of neat hacking on wireless, and just about everything you'd expect to be able to do from a Windows machine, except make the battery last. Even after the standard optimizations (like cpufreq, laptop_mode, brightness, turning off useless processes, etc.) my battery still only lasts about an hour running under Linux as opposed to 2 1/2 hours in Windows. Has anybody come up with some innovative battery conservation ideas for Linux? It seems to be the only thing lacking in this fine operating system." What kernel options might one look into, for saving laptop battery power? Also, what desktop settings (both for Gnome and KDE) would work best, for this situation?
A WindowManager that uses less cup and graphics horsepower may help with your battery life. IceWM is available in many distros and you can run Gnome or KDE from within IceWM when you need to.
Well, your windows machine is probably throttling down the processor when you're unplugged. It's possible that your linux machine doesn't do that.
I've got a T40, probably the same graphics card as the poster (Mobility Radeon 7500) and I can't figure out how to enable the power saving features under Linux. I know when I'm in windows power saving the vid card gives me a huge longetivity boost life.
Anyone know how to do that with Linux?
perhaps build a root ramdisk with the most commonly used apps? Then you could spin down and unmount your hd partitions. 'course you would lose your data if you unexpectedly kill the laptop.
It may be the winmodem, or some other win-peripheral (sp?). IIRC, these load the batter a bit, and if they default to on, that would be a problem.
service pcmcia stop /dev/dvd /dev/hdaX
service lpd stop
hdparm -E 4
hdparm -S 12
if
Remember that most applications have no awareness of your desire to conserve battery life. In particular, disabling your web browser's disk cache will prevent your disk from spinning up and staying that way when you web surf. Think about what applications you're using, and how you can modify their behavior.
I currently run Linux on my Dell Inspiron 8200 and get about 1 hour more battery runtime than in Windows XP or 2000. Stock, with OEM Windows XP I would peak at about 2.5 hours of battery time, as opposed to peak of 3 hours running Linux. I have since used the i8k-tools (obviously not for Thinkpad) to control things like temperature thresholds to trigger the fans. Not sure about your laptop, but mine has 2 fans, so spinning those down if possible saves a lot of battery time. With the fans running at about 5k RPM as opposed to 9K RPM (full speed) I easily save 45 minutes, making my top peak with Linux damn near 4 hours. Your best bet to save battery life would have to be to find some thinkpad-specific software to slow the fans down and speed up at given temperatures. (not sure if that tpctl can do that or not)
while true ; do echo this is my sig; done
Why not kill syslogd entirely? If you don't need it running, kill it. It's not a server, and unless you're experiencing failure of some sort; or some other loss of functionality why run syslogd on a notebook/portable. If nothing else, set your console to be /dev/ttyS0 and set your syslogd/klogd to output to the serial port. At least this way you could debug your machine if it started acting funny.
I recommend reading up on some of the tricks that embedded people (like me) use. There are a ton of ways to save power and drive-time.
I've never seen it (in a laptop; but I have it in my car) - it's not hard to replace a hard disk with a CFcard. Use the 2.5" hard disk for media/games/etc... but use a 512 or 1G cfcard for the OS/system. As such you can save a ton of energy by not having drive motors spinning up/down, etc.
Don't think that a small group of dedicated individuals can't change the world. It's the only thing that ever has.
Hard drive usage eats battery faster than your CPU by far. Max out your RAM and use something like noflushd to minimize the number of times your hard drive has to spin up. Those are the easiest ways to increase battery life.
Charge your computer whenever you can (the less you drain Li-Ion batteries, the longer they last - there is no "memory effect", so *don't* drain them fully)
I'm not sure if it applies to Li+ - I believe it dos - but many rechargable batteries are cycle-limited. That means that the more often you flip them to charge-mode, battery-mode, charge-mode.. the faster you run out of cycles. Eventually, they just don't charge anymore.
If my previous laptop battery is an example of this, it was charging just fine until one day it just stopped charging/draining at all above about 1-6%