Laptop woes

[Ater Phasma]

I primarily use a laptop (college, you know how it is) and I've found Linux to be far superior to Windows in many areas. Gaming aside (I generally keep a Windows install just for this purpose, as I'm too lazy to monkey with Cedega), my main issue with Linux is my laptop's battery life.

 

Specifically, my battery life is approximately half what it would be in Windows. I've tried using Ubuntu/Kubuntu and Gentoo (I run it on my home box happily, so I figured I'd be able to do it properly on my laptop as well) and I couldn't get battery life to be anything close to what I'd like and what I require.

 

My laptop is an HP Compaq nc8430 with an Intel Core Duo T2500 2.00 GHz processor. I know there's an implementation of SpeedStep or equivalent that the processor uses, and I watched the frequency change with the performance monitor in Kubuntu, so I know that distribution at least uses the scaling properly. But even with the freq. knocked down to 1 GHz, my battery kept draining twice as fast as windows.

 

I'm generally horrible at using google to search for things, so if this sort of issue has been addressed elsewhere, I haven't found it.

 

Any suggestions?

 

p.s. I hope this is an acceptable place to post this topic.

[anyweb]

hi and welcome to the forums, we are also on IRC EFNET join #linux-noob

 

open a console and type this

 

cat /proc/cpuinfo

 

paste the results of that here,

 

cheers

anyweb

[Ater Phasma]

Well, I had to boot off my little Gentoo USB boot disk, considering that I have Windows installed right now.

 

Anyway, here's what you want:

 

processor : 0

vendor_id : GenuineIntel

cpu family : 6

model : 14

model name : Genuine Intel® CPU T2500 @ 2.00GHz

stepping : 8

cpu MHz : 1995.120

cache size : 2048 KB

physical id : 0

siblings : 2

core id : 0

cpu cores : 2

fdiv_bug : no

hlt_bug : no

f00f_bug : no

coma_bug : no

fpu : yes

fpu_exception : yes

cpuid level : 10

wp : yes

flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx pni monitor vmx est tm2 xtpr

bogomips : 3997.29

 

processor : 1

vendor_id : GenuineIntel

cpu family : 6

model : 14

model name : Genuine Intel® CPU T2500 @ 2.00GHz

stepping : 8

cpu MHz : 1995.120

cache size : 2048 KB

physical id : 0

siblings : 2

core id : 1

cpu cores : 2

fdiv_bug : no

hlt_bug : no

f00f_bug : no

coma_bug : no

fpu : yes

fpu_exception : yes

cpuid level : 10

wp : yes

flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx pni monitor vmx est tm2 xtpr

bogomips : 3990.17

 

Remember that this was running off a Gentoo LiveUSB disk, so there are no scaling options and such that are being utilized.

[znx]

Specifically, my battery life is approximately half what it would be in Windows. I've tried using Ubuntu/Kubuntu and Gentoo (I run it on my home box happily, so I figured I'd be able to do it properly on my laptop as well) and I couldn't get battery life to be anything close to what I'd like and what I require.

 

This is very true, Linux systems are generally known to be more consumption by default. However not all is lost. You can make adjustments to the system to greatly improve the lifetime.

 

But even with the freq. knocked down to 1 GHz, my battery kept draining twice as fast as windows.

 

Although it can be a source to improve the battery life, normally its more intensive actions that cause power loss. Particularly disk actions.

 

After browsing a bit I discovered an article that lists a few ideas to improve your battery life.

 

For instance it talks about adding "noatime" to your ext3 mounts. This is a good idea as it reduces the amount of disk actions. It continues to purge certain items from syslogd, again by 'devnulling' the logs it no longer write them to disk. If you are running ntp, remove it again its a source of constant writes to the disk.

 

These are all good suggestions if you are using the laptop then stopping for a few minutes .. and using it again. Constant usage will still enable the disk and therefore not really benefit from spinning the disk down.

 

It is a well discussed thing, as you can see by the fact that the Linux 2.6 kernel has a laptop_mode you can also take a look at Smart Spindown by the same guy. Finally CPUdyn also has some disk spindown abilities.

 

All in all the trick to expanding the lifetime is reduction. Good luck!

[Ater Phasma]

Hey, thanks... maybe I can get the battery to last a decent length of time now.

 

The laptop_mode article (found through the link you provided) seems to indicate that setting up the laptop_mode thing is a very extensive and confusing process. Something about extracting scripts from the laptop_mode kernel documentation, which confuses me. Is there an easier way to do it?

 

<edit> My mistake, I didn't quite get what the initial page said. Laptop mode tools. I'll be checking that out. </edit>