Introduction

All TLP settings are stored in the config file /etc/default/tlp. The default configuration provides optimized power saving out of the box. Some advanced features like turning off the optical drive and battery thresholds need to be activated explicitly.

The config file can be changed with any text editor (root privilege is needed). For example:

Changes to the settings take effect after a reboot, a change of the power source or directly by

Hint: when installing updates of TLP, the package manager asks for confirmation before overwriting a changed config file with an updated version.

Parameters

Power Saving

General hints:

• Parameters ending on _AC are effective with the power supply connected
• Parameters ending on _BAT are effective when running on battery
• Parameters containing blanks must be enclosed in double quotes ("")
• Some parameters are inactive by default; remove the leading '#' to activate

General

Set to 0 to disable TLP (Reboot needed).

File System

Values > 0 activate kernel laptop mode. No changes needed.

Timeout (in seconds) for writing unsaved data in file systems buffers to disk.

Processor and Frequency Scaling

Selects the cpu scaling governor for automatic frequency scaling. Possible values are ondemand (default), powersave, performance and conservative.

Important:

• The default setting ondemand is sufficient for almost all workloads, you should know exactly what you're doing if you change this!
• You must disable your distribution's governor settings or conflicts will occur. See the TLP FAQ.

Set the min/max frequency available for the scaling governor. Possible values depend on your CPU. For available frequencies consult the output of tlp-stat, Section "+++ Processor". A value of 0 means to use processor defaults.

Hint: after enabling the processor defaults a restart is required to ensure that the new setting takes.

Important: lowering the max frequency on battery power does not conserve power. The best results are achieved by the ondemand governor without frequency limits.

Disable cpu "turbo boost" (Intel) or "turbo core" (AMD) feature (0 = disable / 1 = allow).

Hints:

• Requires Linux 3.7 and above
• A value of 1 does not activate boosting, it just allows it
• This may conflict with your distribution's governor settings

Minimize number of used cpu cores/hyper-threads under light load conditions (1 = enabled, 0 = disabled). Depends on processor model.

Kernel

Activate kernel NMI watchdog timer (0 = disabled/save power, 1=enabled). A value of 1 is relevant for kernel debugging only.

Undervolting

Hint: advanced Linux skills are necessary to use this feature.

Frequency/voltage ID pairs for the undervolting of Intel processors. Assumes that a kernel with PHC patches is installed. For more information see the PHC wiki.

Disks and Controllers

Device Assignment

Defines the disk devices the following parameters are effective for. Multiple devices are separated with blanks.

When using a 2nd disk in a swappable drive slot or the Ultrabay, the assignment of device names by the kernel (sda/sdb) can change possibly. In this case it is advisable to do the device assignment using IDs:

The command

shows the IDs of all attached disks.

Advanced Power Management

Set the "Advanced Power Management Level". Possible values range between 1 and 255:

• 1 – max power saving / minimum performance – Important: this setting may lead to increased disk drive wear and tear because of excessive read-write head unloading (recognizable from the clicking noises)
• 128 – compromise between power saving and wear (TLP standard setting on battery)
• 192 – prevents excessive head unloading of some HDDs
• 254 – minimum power saving / max performance (TLP standard setting on ac)
• 255 – disable APM (not supported by some disk models)

Different values for multiple disks are separated with blanks.

Spin Down

Timeout value until the spindle motor stops when the disk is idle. Valid settings:

• 0 – disabled
• 1..240 – timeouts from 5 seconds to 20 minutes (in increments of 5 seconds)
• 241..251 – timeouts from 30 minutes to 5.5 hours (in increments of 30 minutes)

Different values for multiple disks are separated with blanks.

SSDs don't have moving parts, therefore this setting is "don't care" for them and can remain disabled.

Hint: stopping the system disk for extended periods of time is unlikely to work, because applications and system daemons wake up the disk frequently. However for a 2nd disk in a swappable drive slot or the Ultrabay that is not accessed permanently, this setting may be quite useful.

Disk I/O Scheduler

Sets the I/O scheduler per disk. Possible values:

• cfq – Linux default, suggestion for both conventional HDDs and SSDs
• deadline – alternative for SSDs
• noop – alternative for SSD

Different values for multiple disks are separated with blanks.

SATA Aggressive Link Power Management

Sets the power management mode for the SATA links connecting disk and optical drives. Possible values:

• min_power – max power saving / minimum performance
• medium_power – compromise between power saving and performance
• max_performance – minimum power saving / max performance

PCI Express Bus

Active State Power Management

Sets PCIe ASPM power saving mode. Available with kernel 2.6.35 and above. Possible values:

• default
• performance
• powersave

Graphics Cards

Radeon

Controls the graphics card's clock. Available with kernel 2.6.35 and above. Supported by the radeon driver, not fglrx. Possible values:

• low
• mid
• high
• auto – mid on battery, high on ac
• default – uses hardware defaults, clock control disabled

Hint: this setting makes the display flicker briefly upon changing the power source.

Networking

Wifi Power Management

Sets wifi power saving mode. Adapter support depends on kernel and driver. Possible values:

• 1 – disabled
• 5 – enabled

Hint: power save can cause an unstable wifi link.

Wake On LAN

• Y – Wake on LAN disabled
• N – Wake on LAN enabled

Hint: after enabling a restart is required to ensure that the new setting takes.

Audio

Timeout (in seconds) for the audio power saving mode (supports Intel HDA, AC97). A value of 0 disables power save.

Hint: this setting can cause slight clicks in sound output.

• Y – powers off the controller together with the sound chip
• N – controller active permanently

Drive Slot / Ultrabay

• 1 – power off the optical drive on battery
• 0 – optical drive powered on permanently

Device file for the optical drive (default: /dev/sr0).

Hints:

• Re-power the drive by releasing and reinserting the drive slot/Ultrabay eject lever; on newer models push the media eject button
• Devices other than optical drives – in particular hard disk drives – are not affected by this setting

Runtime Power Management

Controls runtime power management for PCI(e) bus devices. Available with kernel 2.6.35 and above. Possible values:

• auto – enabled (power down idle devices)
• on – disabled (devices powered on permanently)

Controls which PCI(e) devices are considered for runtime power management:

• 0 – only selected devices (safe default)
• 1 – all devices (experimental)

Warning: RUNTIME_PM_ALL=1 is an experimental feature, it may cause problems with reboot and shutdown.

USB

Set autosuspend mode for all USB devices upon system start or a change of power source. Input devices like mice and keyboards are exluded by default. Possible values:

• 1 – enable
• 0 – disable

Exclude USB devices from autosuspend mode. Useful for devices having difficulties in waking up from autosuspend. Use lsusb to determine IDs. Multiple IDs are separated with blanks.

Disables USB autosuspend mode upon system shutdown. This is intended as a workaround if suspended USB devices disturb the shutdown process.

System Start and Shutdown

Restores radio device state (builtin bluetooth, wifi, wwan) from previous shutdown on system startup:

• 0 – disable
• 1 – enable

Hint: the parameters DEVICES_TO_DISABLE_ON_STARTUP/SHUTDOWN below are ignored when this is enabled.

Disables builtin radio devices upon system start:

• bluetooth
• wifi – Wireless LAN
• wwan – Wireless Wide Area Network (UMTS)

Multiple devices are separated with blanks.

Hint: this feature is not available for all laptops. It depends on rfkill support for your model.

Linux enables all builtin radio devices by default. In case of exception you can use this setting to enable the missing devices upon system startup. Possible values are as above.

Disables builtin radio devices upon system shutdown. May be used as a workaround when enabled radio devices block the shutdown process. Possible values are as above.

Enables builtin radio devices upon system shutdown. May be used as a workaround to prevent other operating systems from missing disabled devices. Possible values are as above.

Wireless Radio Switch

ThinkPads / Ubuntu only

Radio devices to enable when wireless radio switch is turned on.

Hint: this feature is only available for ThinkPads with a slide switch (not Fn+F5!) running Ubuntu.

Battery Charge Thresholds

ThinkPads only

Set ThinkPad battery charge thresholds for main battery (BAT0) and auxiliary/Ultrabay battery (BAT1). Values are given as a percentage of the full capacity.

Charging starts upon connecting AC power, but only if the remaining capacity is below the value of START_CHARGE_TRESH (lower threshold). Charging stops when reaching the STOP_CHARGE_TRESH (upper threshold) value. If, however when you connect the AC adapter, charge is above the lower threshold, then it will not charge.

The default configuration file provides sample settings designed to minimize battery wear – the battery is charged to 80% only. However these settings are disabled by default and must be enabled explicitly by the user (remove the leading '#'). Note that even the hardware defaults of 96 / 100% – effective without TLP – already prevent battery wear by blocking short charge cycles.

Hint: the charging process is not controlled by software, but by hardware. TLP just writes the thresholds to the hardware registers (via tp-smapi or tpacpi-bat).

Disable use of tpacpi-bat – and use tp-smapi instead – for setting the charge thresholds on Sandy Bridge models (X220, T420 et al.) .

Hint: do not use this option with Ivy Bridge models (X230, T430 et al.) where tpacpi-bat is mandatory because tp-smapi does not work.

For further questions concerning battery thresholds consult the TLP FAQ.

Radio Device Wizard

The radio device wizard provides the capability to enable or disable builtin radio devices triggered by certain events. In Ubuntu and Debian it is implemented in the (optional) package tlp-rdw.

Hint: the radio device wizard needs Network Manager as a prerequisite.

Disable on Network Connect

Upon a lan, wifi or wwan connect the stated radio devices are disabled:

• bluetooth
• wifi – Wireless LAN
• wwan – Wireless Wide Area Network (UMTS)

Multiple devices are separated with blanks.

Enable on Network Disconnect

Upon a lan, wifi or wwan disconnect the stated radio devices are enabled.

Enable/Disable on Dock

After docking the stated radio devices are enabled/disabled.

Enable/Disable on Undock

After undocking the stated radio devices are enabled/disabled.

Trace Mode

For support purposes TLP provides a trace mode. To enable it add the following line to the configuration file:

Default Configuration

For reference see /etc/default/tlp as contained in the installation package.

Links

TLP

• TLP Linux Advanced Power Management – Installation instructions and user documentation
• TLP FAQ
• TLP Developer Documentation – Packaging instructions

Other

• I/O scheduling – Wikipedia article
• Laptop Mode – Kernel laptop mode documentation
• PCIe ASPM – PCI Express Active State Power Management
• PHC wiki – PHC documentation
• Radeon driver documentation – see "KMS Power Management Options"
• rfkill – Kernel framework for switching radio devices
• Runtime power management – Kernel documentation
• tp-smapi – tp-smapi documentation at thinkwiki.org
• USB Auto Suspend

© 2013, linrunner. Licensed under the CC BY-NC-SA.