[ltp] How to improve battery life on Thinkpad X60s

[John Fremlin]

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.]