IBM ThinkPad X41

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The X41 and X41t (tablet) are both SATA-based machines that include a SATA-PATA bridge allowing the use of PATA HDDs, see external links for modifications to use SATA HDDs and SSDs. The laptops utilise a Pentium M processor (either 1.5GHz or 1.6GHz), the Linux-ck packages contain optimised packages for this architecture.

This article contains some useful tweaks to make the most of your machine, the tweaks are mainly powersaving biased. With vanilla Arch, around 3 hours battery life was achieved, following powersaving tweaks a bit over than 5 hours was achieved, this was performed with screen brightness at the second highest value.

Useful packages

Some useful packages for your IBM/Lenovo ThinkPad X41:

System Packages

  • acpi - provides /proc/acpi, interesting things like lid state, temperatures, volume, brightness etc.
  • xf86-input-wacom - Driver supporting Wacom tablet screen.
  • xf86-video-intel - Xorg driver for the Intel 915GM graphics chip.
  • tp_smapi - Adds support for SMAPI functions (battery discharge control, battery information, hdaps acceloremeter support).
  • thinkfinger - Driver for fingerprint reader.

The IBM X41 comes with a ipw2915 wireless Centrino (A, B and G) or ipw2200 wireless Centrino (B and G) module, the ipw2200 module provides support for these too devices. netctl has been tested and works flawlessly with the ipw2915.


Note: Thinkfan seems to fail due to thinkpad_acpi not having a fan_control function
  • thinkfanAUR - Control the utilisation of the fan.
  • gpm - Linux console mouse server.

General Tweaks

Scrolling with trackpoint

The following file can be added for trackpoint scrolling support in X.


Section "InputClass"
        Identifier      "Trackpoint Wheel Emulation"
        MatchProduct    "TPPS/2 IBM TrackPoint|DualPoint Stick|Synaptics Inc. Composite TouchPad / TrackPoint|ThinkPad USB Keyboard with TrackPoint|USB Trackpoint pointing device"
        MatchDevicePath "/dev/input/event*"
        Option          "EmulateWheel"          "true"
        Option          "EmulateWheelButton"    "2"
        Option          "Emulate3Buttons"       "false"
        Option          "XAxisMapping"          "6 7"
        Option          "YAxisMapping"          "4 5"

Taken from Xorg#Example: Wheel emulation (for a Trackpoint)

Powersaving tweaks

Initially without any powersaving tweaks, the X41 uses quite a lot of power (this can be monitored using powertop, it also provides suggestions for reducing power consumption). Here are some modifications that I found considerable improved the battery life of the X41t.

laptop-mode (kernel)

Laptop mode is included in the kernel, it buffers disk activities to reduce utilisation of your HDD therefore saving a considerable amount of power. The effect with SSDs is less pronounced, but still saves some power.

echo "vm.laptop_mode=5" | sudo tee /etc/sysctl.conf/laptop_mode.conf"

SATA-ALPM (pm-utils)

ALPM - Aggressive Link Power Management allows the SATA host bus adapter to enter a low power state when inactive therefore reducing power consumption.

echo "SATA_ALPM_ENABLE=true" | sudo tee /etc/pm/config.d/sata_alpm
sudo chmod +x /etc/pm/config.d/sata_alpm

Powersaving on PCI devices

Powersaving isn't automatically enabled on devices as sometimes it causes issues, this can save about 2W.

ACTION=="add", SUBSYSTEM=="pci", ATTR{power/control}="auto"

i915 RC6 powersaving

The i915 chipset supports a variety of powersaving features, checkout modinfo i915 \| grep -i power for all options. The following are a good set to enable.

options i915 i915_enable_rc6=7 i915_enable_fbc=1 lvds_downclock=1 

RC6 is a powersaving protocol, 7 enables RC6, deep RC6 and deepest RC6 (refer to Power Management#Enable RC6 Power Save Options for more information). i915_enable_fbc=1 enables framebuffer compression reducing the time taken to update the screen. lvds_downclock=1 lowers the clockrate of the screen.

Disable NMI watchdog

The NMI watchdog is a debugging feature of the linux kernel that is enabled by default. It is useless for normal operation and significantly increases the number of CPU wakeups/second.

echo "kernel.nmi_watchdog=0" | sudo tee /etc/sysctl.conf/nmi_watchdog.conf


PHC - Processor Hardware Control. intel-phcAUR supports the Mobile Centrino line of processors and hence the X41, this program allows you to undervolt your CPU. Undervolting reduces the voltage(V) the processor runs at, because P=IV this will reduce your power consumption, this has no effect on performance, any excess voltage will be dissipated as heat, your laptop will run cooler and the fan will activate less frequently.

$ yaourt -S intel-phc
$ phc-intel setup # To install drivers
$ yaourt -S linux-phc-optimize
$ sudo linux-phc-optimize # Repeat this each time the laptop crashes until you've got a full set of parameters, this is 9 times

Once you have established stable VIDs, adding them to system startup can be accomplished modifying the intel-phc configuration file. If it doesn't exist, create it

 VIDS="17 15 13 11 9 7 5 4 4"  

You can check that this is enabled on your next reboot by sudo intel-phc status

Tablet support

The X41t utilises a Wacom digitiser for input, pacman -S xf86-input-wacom provides support for it. Once installed the driver should be activated following the next reboot or modprobe xf86-input-wacom.

External links