[ltp] X60 power consumption

[Nils Faerber]

Richard Neill schrieb:
> Nils Faerber wrote:
> Thanks, Nils,

You're welcome!
It is a very annoying topic though. I never had to worry about this
stuff and manually setting it to something with my X31...

>> echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
>> hdparm -B 254 /dev/sda > /dev/null
>> ifconfig eth1 up
>> echo 7 > /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/power_level=

>> echo 5 > /proc/sys/vm/laptop_mode
>> ethtool -s eth0 wol d
>> echo 1500 > /proc/sys/vm/dirty_writeback_centisecs
>> echo "auto" > `hal-get-property --udi \
>> /org/freedesktop/Hal/devices/usb_device_483_2016_noserial --key \
>> linux.sysfs_path`/power/level
>> echo min_power > /sys/class/scsi_host/host0/link_power_management_poli=
cy
>> echo shutdown > /sys/power/disk
>=20
> Very useful. Am I correct in assuming that laptop-mode is irrelevant if=

> I have an SSD?

Well - also accesses to the SSD will cause bus activities and CPU
activity. So doing nothing also saves power. Not much of course.

>> Using this I can get about 9 to 9.5W with WiFi enabled which is IMHO O=
K.
>> (And no need to unload the uhci-hcd module...)
>>
>> It is still way too much and the fan still spins almost all the time b=
ut
>> a lot of the power now goes into the chipset and graphics and there is=

>> little we can do there - at least from what I know.
>=20
> I'm still at 11W here.

This is strange.
Let's recheck...hmm... today here in the office I also get pretty
exactly 11W with WiFi (though I cannot dim the backlight to minimum
again :( and about 10W without WiFi. Strange.

> I did get the fan to stop, very useful to simply install tp-fand, and
> set the thresholds to 65 degrees. This is too hot for lap-top use, but
> fine for a table.
> http://www.gambitchess.org/mediawiki/index.php/ThinkPad_Fan_Control#Ubu=
ntu_8.04_.2F_8.10_.2F_9.04

I am not in favour of this, sorry. If my machine gets hotter that the
default threshold of ~45=B0C it shall toggle the fan. But it should not
get that hot in the first place! Heat means energy and this comes from
my battery! So less heat, less power consumption, longer battery life.

>> If you have it installed watch the powertop output and see if your CPU=

>> stays in C4 most of the time. If not, find the course.
>=20
> Aha. I am almost always in C3 (at 1GHz) but never see C4. It's not even=

> shown as an possibility in powertop. Any ideas why this could be?

Oh ho ho - my bad, I did not recheck that, it is C3 of course, not C4.
The CPU does support C4 but the BIOS does not. So C3 is the lowest we
see in Linux.

> Richard
Cheers
  nils faerber

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