My thinkpad t420s doesn't last 2 hours

Question

hardware and software:
* thinkpad t420s, brand new with standard battery
* CPU: i7-2640M CPU @ 2.80GHz, 4 cores. frequency scaling is enabled, they all usually run at 800MHz (ondemand governor)
* intel SSD, no HDD
* wifi: iwlwifi: Intel(R) Centrino(R) Advanced-N 6205 AGN, REV=0xB0
* thinkfan is installed, but couldn't get it configured properly. TODO
* kernel args
[dieter@dieter-t420s ~]$ cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-linux root=/dev/mapper/cryptpool-root ro root=/dev/mapper/cryptpool-root cryptdevice=/dev/sda3:sda3crypt:allow-discards ro add_efi_memmap i915.modeset=1 i915.i915_enable_rc6=1 i915.i915_enable_fbc=1 i915.lvds_downclock=1 pcie_aspm=force quiet quiet add_efi_memmap
bios options:
* graphics is set to optimus (though i don't have bumblebee/optimus enabled right now, I haven't needed to attach an external display). TODO  force "built-in GPU" in bios, maybe that helps.
* intel speedstep set to optimal battery usage when not on AC
* adaptive thermal management set to "balanced" (it's that or performance)
* cpu power management enabled
* pci-e power management enabled
test:with some basic usage (say 40 min of browsing over wifi and watching some vids, and the rest idle) it doesn't last 2 hours. (about 1h50min)
although I think I have all the most important things taken care of, I'll also have a look at https://bbs.archlinux.org/viewtopic.php?id=134109 and maybe laptop mode tools (I did look at it, but as i don't have a HDD and i have frequency scaling already enabled...)
I'll also need to try some power diagnostic tools like powertop or whatever it was.
any more tips? this is kindof disappointing, I was expecting 4-5-6 hours.. thanks!
Last edited by Dieter@be (2012-05-22 08:54:48)

Answer 1

Dieter@be wrote:
jdahm wrote:
I have a T420 (didn't want to bother with the dedicated GPU) and get 6+ hours.  I followed the steps on 'Laptop' on the wiki, installed tp_smapi, thinkfan, granola, etc.
i also had trouble getting thinkfan to work.  The trick I found with it is to stop the daemon and launch it manually (with the -n flag, as shown in the rc.d daemon script) to see what it complains about.  After a few iterations to thinkfan.conf the daemon seemed to start without problem.  This thread (found on the thinkwiki AUR page) helped me the most: http://ubuntuforums.org/showthread.php?t=1749186&page=1.
thanks, so what's your thinkfan config?
Here it is.  Hope this is helpful.  You'll probably need to run that find command and replace the four lines which start with "sensor".
## Notes:
# sources:
# + [url]http://ubuntuforums.org/showthread.php?t=1749186&page=1[/url]
# Use this command to find devices:
# find /sys/devices -type f -name "temp*_input"
# Specify the fan to use
fan /proc/acpi/ibm/fan
# Sensors
sensor /sys/devices/platform/coretemp.0/temp1_input
sensor /sys/devices/platform/coretemp.0/temp2_input
sensor /sys/devices/platform/coretemp.0/temp3_input
sensor /sys/devices/virtual/hwmon/hwmon2/temp1_input
#(0, 0, 55)
#(1, 48, 60)
#(2, 50, 61)
#(3, 52, 63)
#(4, 56, 65)
#(5, 59, 66)
#(7, 63, 32767)
# More conservative settings
(0, 0, 35)
(1, 33, 38)
(2, 36, 45)
(3, 39, 49)
(4, 46, 58)
(5, 50, 62)
(7, 56, 32767)
Last edited by jdahm (2012-05-24 01:29:35)