Laptop Mode Tools is a laptop power saving package for Linux systems. It is the primary way to enable the Laptop Mode feature of the Linux kernel, which lets your hard drive spin down. In addition, it allows you to tweak a number of other power-related settings using a simple configuration file.

To quickly check which modules are enabled, disabled or auto, run:

Spinning down the hard drive through values saves power and makes everything a lot more quiet. LMT can also establish values. The maximum hard drive power saving is 1 and the minimum is 254. For example, set this value to 254 when on AC and 20 when on battery. If you find that normal activity hangs often while waiting for the disk to spin up, it might be a good idea to set it to a higher value (e.g. 128) which will make it spin down less often. and values are configured in .

With the variable (default on), laptop-mode-tools automatically remounts your partitions, appending in the mount options. This keeps the journaling program jbd2 from accessing your disk every few seconds, instead the disk journal gets updated every 10 minutes.

From the official, upstream FAQ:

Question: I have a solid-state disk (SSD) in my machine. Should I enable any of the disk-related parts of laptop-mode-tools, or are they irrelevant?

Answer: They may be relevant, because (a) laptop mode will reduce the number of writes, which improves the lifetime of an SSD, and (b) laptop mode makes writes bursty, which enables power saving mechanisms like ALPM to kick in. However, your mileage may vary depending on the specific hardware involved. For some hardware, you will get no gain at all, for some the gain may be substantial.

For this you need to have a CPU frequency driver installed. See CPU frequency scaling.

Enable the Intel SATA AHCI controller Aggressive Link Power Management feature to set the disk link into a very low power mode in the absence of disk IO.

Available brightness values for certain laptops can be obtained by running following command:

For ThinkPad T40/T42 notebooks, minimum and maximum brightness values can be obtained by running:

For ThinkPad T60 notebooks, minimum and maximum brightness values can be obtained by running:

For most (probably all) Asus ROG & TUF notebooks with Intel CPUs, a maximum brightness value can be obtained by running:

Asus notebooks talk to the kernel though an Asus specific module and as such standard keyboard brightness commands will not work. A maximum brightness levels can be obtained by running:

Wireless interface power management settings are hardware-dependent, and thus a bit trickier to configure. Depending on the wireless chipset, the settings are managed in one of the following three files:

Note that activating the three of them should not be much of a problem, since LMT detects the module used by the interface and acts accordingly.

The supported modules for each configuration file, indicated above, are taken directly from LMT. However, this seems to be a bit out-of-date, since the current 2.6.34 kernel does not provide the ipw3945 and iwl4965 modules anymore (3945 chipset uses iwl3945 instead, and 4965 uses the generic module iwlagn). This is only brought here for information, as this does not (or should not) affect the way LMT works.

There is a known issue with some chipsets running with the iwlagn module (namely, the 5300 chipset, and maybe others). On those chipsets, the following settings of :

If that does not help, go through the laptop-mode configuration files and make sure that the service you want to enable is set to 1. Many services (including cpufreq control) are by default set to "auto", which may not enable them.

Issues with bluetooth not working when booting up with battery are fixed with disabling runtime-pm.

When laptop mode is enabled, KDE fails to start. The reason is that the default KDE display manager (SDDM) starts before the NVIDIA driver. To prevent this from happening you need to remove the kernel parameter.

As described before, laptop-mode-tools affects the NVIDIA driver. Adding the kernel parameter reduces boot time dramatically.