power usage too high (unbelievably high)

[Roberto]

Hi,
I use powertop to monitor my pentium-M Dothan processor (on a Toshiba
A80-111) but I always get  extremely high power usage estimates.


Cn                Avg residency       P-states (frequencies)
C0 (cpu occupata)      ( 3,4%)          1,60 Ghz     0,0%
C1                0,0ms ( 0,0%)         1333 Mhz     0,0%
C2                5,2ms ( 5,4%)         1067 Mhz     3,4%
C3                0,9ms ( 0,2%)          800 Mhz    96,6%
C4               22,5ms (91,0%)

Wakeups-from-idle per second : 53,1     interval: 10,0s
Power usage (5 minute ACPI estimate) :  **75,0 W (0,5 hours left)**

Top causes for wakeups:
  28,7% ( 14,9)                 X : do_setitimer (it_real_fn)
  19,8% ( 10,3)   thunderbird-bin : futex_wait (hrtimer_wakeup)
  19,6% ( 10,2)            kicker : schedule_timeout (process_timeout)
  11,3% (  5,9)       <interrupt> : ipw2200
   4,2% (  2,2)       <interrupt> : libata
   2,7% (  1,4)    wpa_supplicant : schedule_timeout (process_timeout)


I can't believe my laptop is draining so much power, where's my mistake?

I use the latest bios version.
My kernel is gentoo-sources-2.6.23-r with hrt patchset and acpi enabled.
The battery is quite old. It last no more than 45 minutes. However I
don't know whether it would work better under windows or not.
Strangely when the battery reaches 0% the laptop keeps going on for
almost 10 minutes!

I can't make historical comparisons because I've just switched back to
gentoo from ubuntu moreover I haven't used the battery for two months..

Can you suggest me a list of things I should check in order to find the
reason of such a behaviour? I'll provide you any information you need.

Thank you in advance.

Best regards,
Rob