[ltp] How to improve battery life on Thinkpad X60s

[Martin Aumueller]

See below what Florian Reitmair wrote on the matter a couple of days ago (6. 
Sep) on this mailing list. Search the archive (e.g. at 
http://marc.theaimsgroup.com/?l=linux-thinkpad&r=1&w=2) for viewing the whole 
thread.

However, even with these suggestions it is impossible for me to reach 7 W. 
However, you might be able to significantly reduce power consumption w/o 
removing all modules.

---------------------------


> > - a SD Card for the home directory
this is easy, just buy one, use the newst kernel and put your home on it.

> > - use the busybox syslog daemon instead of syslogd and klogd
The busybox syslogd is nice, it uses a memory buffer for logs. On my laptop
there is no need for longterm logfiles. Under debian just install busybox.
then use some startup script like:

/etc/init.d/sysklogd stop
/etc/init.d/klogd stop
busybox klogd
busybox syslogd -C 16

now you can use the command "busybox logread" to get the last 16kb of logs.

> > - disable the internal USB bus for bluetooth and the fingerprint reader so
> >     the laptop always can use C3/C4 even if the uhci_hcd is loaded (this 
can
> > be done with unbind in the sysfs)

http://lwn.net/Articles/143397/

in my thinkpad and X60s there is an internal USBV1 bus, and the kernel
activate that bus, because there is the fingerprint reader on it (and
bluetooth).

just unbind the usb host controller, and the cpu can use C3/C4. To use
bluetooth it should fairly simple to script the "bluetooth" button to first
bind the bus.. 

> > - dim the display
thats included in the ibm_acpi kernel module

> > - use cpufreq
there are normaly 2 drivers
acpi cpufreq
centrino cpufreq

if you want to use undervolting .. you have to disable the acpi cpufreq in
your kernel build.

> > - use a blank screensaver which disables the display correctly
xscreensaver does this correct, i test it always in a dark room. if the
screensaver successfully disabled the back-light the display is really dark,
if its only blank you can see the back-light.

> > - don't use postfix/exim use ssmtp instead
postfix/exim do periodic scans of the mail spool. normally i don't need a
mailqueue on my notebook. ssmtp is a very simple and direkt MTA which is only
active if i send a mail.

> > - under gnome, disable beagle
if you want to diable your disk when the laptop goes idle, it really is a bad
idea to enable beagle .. it becomes active when the disk should spin down..

> > - use a 2.6.18-rcX kernel and enable alsa-power management
the new 2.6.18 kernels have the nice feature for alsa and e1000 modules to
disable power until the sound device is open / a network cable is detected.

for alsa its an compile time option (in the -mm tree)
for e1000 its an kernel module option

> How do I enable alsa power management? I didn't find a kernel config option.
> 
> > - use a 2.6.18-rcX kernel and use the new e1000 module for more 
powersaving
> 
> What does 'new' mean? The one e1000 module that is included with 2.6.18-rc6 
or 
> is there another module with a different name?

the kernel docu isn't updated yet, but there is a module option:

2.6.18-rc4/drivers/net/e1000/e1000_param.c

/* Enable Smart Power Down of the PHY
  *
  * Valid Range: 0, 1
  *
  * Default Value: 0 (disabled)
  */
E1000_PARAM(SmartPowerDownEnable, "Enable PHY smart power down");

> > - enable wireless powersaving
there are more the one way of enabling this..
normally i use "iwpriv" for the intel 2200 or 3495 and just try a bit for the
right power mode.

> Thank you very much for clarifying this,
np

-- 
Florian Reitmeir



On Fri September 15 2006 01:20, John Fremlin wrote:
> I have a Thinkpad X60s. When running MS Windows XP with maximum
> powersaving it switches down to use less than 7W.
>
> Under Linux (2.6.17), I have brought it down to use about 10W, but
> normally it runs at about 11W.
>
> Why does Linux use so much more power? It also runs hotter (53C
> instead of 42C for both thermal zones), in particular the area on the
> right of the fingerprint reader is noticeably warmer.
>
> The CPUs are at 1GHz, CPU0 alternates between C2 and C3 and CPU1 is
> between C3 and C6. Running with nosmp doesn't seem to help.
>
>
> [The way to bring down the power is to rmmod all unnecessary device
> drivers (irtty_sir irda sir_dev nsc_ircc ohci1394 uhci_hcd ehci_hcd
> e1000 yenta_socket pcmcia pcmcia_core ipw3945 sdhci shpchp pci_hotplug
> bluetooth rfcomm hidp l2cap) and turn off the hard-disk.
>
> By leaving X you can save about 300mW. You can see the power
> consumption with acpitool.]