How to make use of Power Management features

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General Information about Power Management features

This page should give you all the information you need to make use of your ThinkPads Power Management features under Linux and hence effectively enhance your battery life.

Note that different distributions and kernels have different results. ThinkPad-365 and 365X used to perform blank, sleep and hibernation well using HW with W95,OS/2,and Linux installed (1998). Later ThinkPads such as 240X,600E,T20 with recent Debian 2.4 kernels and ACPI=off will sleep, (also MDK-2.6 kernels). However, blank and hibernation to disk do not work. Better results are expected with 2.6.11+.

APM vs. ACPI

All IBM ThinkPads support APM, and a lot support ACPI as well. Newer Lenovo ThinkPads support only ACPI. Quality of ACPI implementation varies from model to model. Both technologies cannot be used simultaneously; you'll have to make a choice. Which to use depends on the model as well as on the state of ACPI support in the kernel.

On older models you are surely better off with APM, if they feature ACPI at all.

It seems that at least in recent models from the A, G, R, T and X series ACPI generally works fine and is a lot more flexible than APM, but with a lot of them also a Problem with high power drain in ACPI sleep has been experienced.

Please check our APM vs. ACPI success table to find out about APM and ACPI support in specific models.

On the other hand simply switching from APM to ACPI extended my X31 battery runtime from about 3.5h to 4h. This had nothing to do with Dynamic Frequency Scaling which was active in both configurations.

TODO
more precise and extended info should be provided here

How to enable certain features

The following links will take you to separate pages dealing with the various topics.

See also

Suspend Resume For users of Lenovo T series Thinkpads who have suspend resume problems related to the Nvidia display card see this page at IBM's Thinkpad support site: http://www-307.ibm.com/pc/support/site.wss/document.do?sitestyle=lenovo&lndocid=MIGR-69135 The driver referenced there (for the Quadro NVS 140M card) works with my T60p and suspends and resumes perfectly to disk. I'll experiment with RAM some day... wcn

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