Power saving

[I_NEED_HELP]

I have just installed mandrake 10.1 on my hp pavillion laptop. I have noticed battery life seems to be a bit shorter then in windows. The battery seems to lat about half an hour longer in windows. Id just like to squeeze a bit more out of battery life if possible.

 

Are there any tools or tips to help me.

[ChrisM]

System>Config'>KDE>Display>Display Power Control

 

Allows you to set standby/suspend/power off times

[coverup]

I have just installed mandrake 10.1 on my hp pavillion laptop.  I have noticed battery life seems to be a bit shorter then in windows.  The battery seems to lat about half an hour longer in windows.  Id just like to squeeze a bit more out of battery life if possible.

 

Are there any tools or tips to help me.

<{POST_SNAPBACK}>

Same here: the battery lasts for about 3.5-4 hours in linux vs 4-4.5 hours in Windows. I am not surprized since the laptop is noticably cooler after running Windows.

[bvc]

There was a thread Madrake runs Hot or something like that...yeah, mandrake runs 10 degrees hotter than any other distro I've used. This started with ML-10/kernel-2.6 So I use the vanilla kernel with mandrake.

[SoulSe]

There are a few reasons I can think of - firstly, as bvc said, Mandrake runs hotter than other distros, but there are ways to cure that.

 

Secondly, there are probably more processes running during a standard session on a out-of-the-box install of Mandrake. To get a list of all the processes running, use:

$ ps aux

This will list them all and you can start doing something about the ones you don't typically need.

 

You could also try switching to a less demanding DE or WM, like Fluxbox.

 

Linux is just generally more demanding out of your system, because it fully utilises it. So think of it this way: you're sacrifising a bit of battery life for an optimally-running system.... and you can probably fix that to. ;)

[iphitus]

Generally on laptops, windows will use any throttling/speed stepping technology that's available as is appropriate.

 

By default, mandrake does not configure these, Go and install cpufreqd through urpmi, allow it to start on boot, then you should see a noticable battery life increase.

 

In 2.6 Kernels you can also enable Laptop Mode. This saves battery power by doing writes to the hard drive less frequently.

You can enable this by running this:

 

echo 1 > /proc/sys/vm/laptop_mode

 

as root. To make this apply on startup, add it to /etc/rc.local.

 

As for killing off unneeded processes, i reckon that's a bit of a misnomer, most of the processes mandrake will start at startup will use little, if any cpu while the computer is running. If they were disabled, you would be unlikely to see any valuable difference in battery life.

 

As for using another wm/de, I dont really think it would be worth it. If you look at top, right now as i have gaim, firefox, gnome, a terminal, cpu usage from them as I type this is only about 1%, so unless you're constantly throwing around your gnome panels, menus, have a lot of applets, you should be ok. I know that in windows, cpu usage usually idles around 8%.... so go figure ;)

 

iphitus

[coverup]

3.5 to 4 hours is with cpufreqd enabled, kernel 2.4. When it runs on battery, the laptop drops 1.6GHz centrino CPU to 600MHz. I agree with iphitus, I don't think killing processes will have any difference, as I stopped all unnecessary services that I could think of. I don't believe switching to 2.6 kernel will make a significant difference either (that's why I don't switch). The power-hungry beast is X - as iphitus suggested, run top when the laptop is idle, and you'll see that. Let's just admit, Windows manages power better than Linux.

[iphitus]

Maybe switch to 2.6, just for that laptop mode extra. The hard drive does tend to chew a bit of power.

[SoulSe]

My bad then. I did, however, notice a difference on an AOpen laptop when I switched from Gnome to Fluxbox and tweaked my processes. But, come to think of it, it wasn't a complete revolution.

 

Sorry, I've been using an Apple iBook for so long, I'm not used to the problems that arise with archaic pc laptops. :P

 

Just kidding... (you have to say that these days).

[Guest krefson]

Maybe switch to 2.6, just for that laptop mode extra. The hard drive does tend to chew a bit of power.

<{POST_SNAPBACK}>

I just noticed a bug in /etc/acpi/actions/battery.sh which prevented it switching the disk

into laptop mode. It contains the line

 

status=`awk '/^state: / { print $2 }' /proc/acpi/ac_adapter/AC*/state`

 

This is incorrect since for me the /proc device is /proc/acpi/ac_adapter/ADP1/state.

Changing the match to A* enables the script to detect my battery status and for the first

time I an seeing hdd power down and only fire up on demand or about once a minute.

(I'm actually running a custom 2.6.9 kernel but this never worked with the stock

2.6.8.1-12mdk so I don't think it's necessarily changed)

 

This is in package suspend-scripts-1.8.1-1mdk in case any Mandrake people are listening.

 

The acpi deamon (you should be running with this on!) should detect the switch to batter

mode and automatically enter this state.

 

Keith Refson