Laptop Powersaving Tips

iphitus · 2009-06-02 02:59:57

Since getting my new eeepc, I've been trying to make it match/exceed the advertised battery life.

So far... I've got the power usage down pretty low while keeping a usable system. Apart from the obvious ones, cpufreq, laptop-mode and brightness, here's some of the things I've found that can help improve battery life...

- Not leaving gmail or ajax intensive pages open. Closing gmail consistently shows a reduction of 1W, sometimes more. With gmail open, both midori and firefox are creating over 100 wakeups a second. I suppose gmail creates a constant traffic, both increasing the wireless use and keeping the CPU awake for longer.

- eee-control from AUR. On windows, Asus netbooks have the "super hybrid engine" which slows the FSB to reduce power usage. eee-control contains an implementation of this and enables many of the FN keys. This saves a few watts.

- wireless power saving. This has killed throughput pretty badly, maxing out at about 20KB/s in pacman, but for web browsing it's fine. Saves quite a bit of power.

The combination of everything has got my power usage down from ~11-12W at use to ~7-9W, and to an idle of ~6-7W. As a result I'm getting at least another hour of battery life, if not more.

What ideas do you guys have?

Last edited by iphitus (2009-06-02 03:10:28)

uncholowapo · 2009-06-02 04:34:08

I use laptop-mode-tools to control everything from my HDD spin downs to my sound powersave feature. But since my battery is out of whack It does a good 45 min. Back then it could do almost 2 hours with mupen64plus running. Also the same for the windows side.

ammon · 2009-06-02 09:41:54

Yep, laptop-mode-tools are the best tool around for power saving.
Try to use as much ram you can. Like, disable hdd cache for ff. That can help a bit.
But linux power saving is far behind windows/mac not cuz the linux guys are lazy, but hardware providers wont cooperate to make it run as it should.
You could also try kernel from Moblin, Intel guys tweaked power saving in it.

Daenyth · 2009-06-02 14:26:49

Perhaps this is worth a wiki page?

fijam · 2009-06-02 16:33:24

I used to hand-pick applications for the lowest possible number of wakeups per second. Some are broken and will use plenty of your battery with a stupid loop on the processor. Some examples: Xfce used to be better than GNOME (dunno currently), abiword is much better than OOo. Generally, it's possible to have less than 10 wakeups/s, assuming that you don't use wifi/mouse/touchpad.

eldragon · 2009-06-02 16:42:05

ive sent the firefox profile to ram, makes the hdd sleep for longer periods of time, same goes with pidgin.

a script backsup every 15 minutes, and when i shutdown, it restores the profile when i turn on the computer.

ammon · 2009-06-02 17:03:47

Can you c/p that script?

eldragon · 2009-06-02 17:16:40

ammon wrote:

Can you c/p that script?

sure, i actually borrowed this from somewhere around the net... here it goes

$  cat .pack_ffox.sh
#!/bin/bash

# Change this to match your correct profile
PROFILE="oqxlxay2.default"
HOME_DIR="/home/eldragon"

# echo "${HOME}"
# echo "${HOME_DIR}"

HOME=${HOME_DIR}
cd "${HOME}/.mozilla/firefox"

if test -z "$(mount | grep -F "${HOME}/.mozilla/firefox/${PROFILE}" )"
then
    mount "${HOME}/.mozilla/firefox/${PROFILE}"
fi

if test -f "${PROFILE}/.unpacked"
then
    tar --exclude '.unpacked' -cpf packed.tmp.tar "$PROFILE"
    mv packed.tar packed.tar.old
    mv packed.tmp.tar packed.tar
else
    tar xpf packed.tar &&\
    touch "${PROFILE}/.unpacked"
fi

some initial setup needs to be done, and a ramfs needs to be setup. so, here comes the fstab entry:

firefox /home/eldragon/.mozilla/firefox/oqxlxay2.default tmpfs size=128M,noauto,user,exec,uid=1000,gid=100 0 0

of course, first manually pack your profile, and clear that folder

von_Wanderlust · 2009-06-03 10:12:59

eldragon wrote:

ive sent the firefox profile to ram.

not exactly the same, but did you know you can use about:config to move the browser cache to ram?

type about:config into firefox address bar
right click in white space to add new string
preference name = browser.cache.disk.parent_directory
value = /tmp

I've used /tmp as I already have that set up as tmpfs in fstab:

none                /tmp    tmpfs   rw,noexec,nosuid,nodev,size=200M   0 0

eldragon · 2009-06-03 13:10:28

dont quote me on this (and im too lazy to find the source), but i think the issue of firefox using the hdd on every page load is not entirely related to the cache.

do a test, let the hdd spin down. and then click on a link (with browser already active). see if the hdd spins up again..

rebugger · 2009-06-03 13:16:21

@eldragon: this could be the source http://www.verot.net/firefox_tmpfs.htm

ammon · 2009-06-03 13:26:42

Type about:config into the Location Bar

Set these preferences to these values....

browser.cache.disk.enable to False
browser.cache.memory.enable to True

I use that for last month. I works fine, i dont think that i need profile in ram.

vacant · 2009-06-03 14:00:58

If you rarely use your laptop on battery, then make sure you do so once a week and let the charge drop to 40% or so before plugging in - extends battery charging capacity for when you do need it.

Lexion · 2009-06-03 14:41:14

@vacant: 0% once a month or so works fine for me.

.:B:. · 2009-06-03 14:57:10

vacant wrote:

If you rarely use your laptop on battery, then make sure you do so once a week and let the charge drop to 40% or so before plugging in - extends battery charging capacity for when you do need it.

Can you explain the rationale behind that?

* B is curious

brazzmonkey · 2009-06-03 21:41:05

B wrote:

vacant wrote:
If you rarely use your laptop on battery, then make sure you do so once a week and let the charge drop to 40% or so before plugging in - extends battery charging capacity for when you do need it.
Can you explain the rationale behind that?
* B is curious

Well, I don't own a eeePC but I confirm you should use your battery every now and then. Otherwise your battery charger will slowly kill your battery. From my own experience, having a laptop constantly plugged to the grid will f*ck your battery in a matter of months (say, from 12 to 18).

uncholowapo · 2009-06-03 21:47:18

I second that. Reading the manual, it explicitly says to let the battery discharge now and then. Otherwise, what would be the point of having a laptop? lol

vacant · 2009-06-03 21:59:05

B wrote:

vacant wrote:
If you rarely use your laptop on battery, then make sure you do so once a week and let the charge drop to 40% or so before plugging in - extends battery charging capacity for when you do need it.
Can you explain the rationale behind that?

Here is the article.

"If you do use the mains as your primary power source - as you might well if the notebook's your main machine - at least make sure you use your laptop on battery power a couple of times a week."

Last edited by vacant (2009-06-03 21:59:22)

iphitus · 2009-06-04 00:26:44

Or alternatively, if you're running on power for long periods, remove the battery altogether. Lion batteries store best at ~40%.

http://www.batteryuniversity.com/parttwo-34.htm

von_Wanderlust · 2009-06-10 05:38:07

eldragon wrote:

dont quote me on this (and im too lazy to find the source), but i think the issue of firefox using the hdd on every page load is not entirely related to the cache.
do a test, let the hdd spin down. and then click on a link (with browser already active). see if the hdd spins up again..

Yeah, I think you are right. It's real hard to tell as my machine is annoyingly loud (T43s have a cooling and bios problem and it constantly blows),but I am sure I can hear it accessing the drive every time I change pages. This is because of the databases it has for history? I thought I turned that stuff off.. Trying not to go too OT, do you think the Firefox 3.5 "private-browsing" mode will fix that? I guess it won't be recording to the database then?

eldragon · 2009-06-10 13:32:35

von_Wanderlust wrote:

eldragon wrote:
dont quote me on this (and im too lazy to find the source), but i think the issue of firefox using the hdd on every page load is not entirely related to the cache.
do a test, let the hdd spin down. and then click on a link (with browser already active). see if the hdd spins up again..
Yeah, I think you are right. It's real hard to tell as my machine is annoyingly loud (T43s have a cooling and bios problem and it constantly blows),but I am sure I can hear it accessing the drive every time I change pages. This is because of the databases it has for history? I thought I turned that stuff off.. Trying not to go too OT, do you think the Firefox 3.5 "private-browsing" mode will fix that? I guess it won't be recording to the database then?

im not sure. i decided it was easier to tweak arch once, than to tweak firefox every time there is a new release. and the database is a nice addition, this way, i dont lose functionality, blindling fast browser history search and a quiet hdd.

Arch Linux

#1 2009-06-02 02:59:57

Laptop Powersaving Tips

#2 2009-06-02 04:34:08

Re: Laptop Powersaving Tips

#3 2009-06-02 09:41:54

Re: Laptop Powersaving Tips

#4 2009-06-02 14:26:49

Re: Laptop Powersaving Tips

#5 2009-06-02 16:33:24

Re: Laptop Powersaving Tips

#6 2009-06-02 16:42:05

Re: Laptop Powersaving Tips

#7 2009-06-02 17:03:47

Re: Laptop Powersaving Tips

#8 2009-06-02 17:16:40

Re: Laptop Powersaving Tips

#9 2009-06-03 10:12:59

Re: Laptop Powersaving Tips

#10 2009-06-03 13:10:28

Re: Laptop Powersaving Tips

#11 2009-06-03 13:16:21

Re: Laptop Powersaving Tips

#12 2009-06-03 13:26:42

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#13 2009-06-03 14:00:58

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#14 2009-06-03 14:41:14

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#15 2009-06-03 14:57:10

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#16 2009-06-03 21:41:05

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#17 2009-06-03 21:47:18

Re: Laptop Powersaving Tips

#18 2009-06-03 21:59:05

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#19 2009-06-04 00:26:44

Re: Laptop Powersaving Tips

#20 2009-06-10 05:38:07

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#21 2009-06-10 13:32:35

Re: Laptop Powersaving Tips

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