IBM ThinkPad X41
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.
Contents
Installation
Grab the .iso file from the download page, write this to a memory sticksudo dd if=archlinux-201x.xx.xx-dual.iso of=/dev/sdX bs=4MRestart the computer and boot into it like any other Arch installation.
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). If you're using Linux-ck try tp_smapi-dkmsAUR (AUR).
- thinkfinger - Driver for fingerprint reader.
- See TrackPoint for track point support.
The IBM X41 comes with a "ipw2915" wireless Centrino (A, B and G) or ipw2200 wireless Centrino (B and G) module, the kernel provides support for these two devices. netctl has been tested and works flawlessly with the "ipw2915". See Wireless network configuration#ipw2100 and ipw2200
Applications
- powertop - Measure power usage.
- cellwriter - (X41t) on-screen tablet keyboard.
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.d/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.
/etc/udev/rules.d/pci_powersaving.rules
ACTION=="add", SUBSYSTEM=="pci", ATTR{power/control}="auto"
i915 RC6 powersaving
See Intel graphics#Module-based Powersaving Options.
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.d/nmi_watchdog.conf
PHC
PHC - Processor Hardware Control. phc-intelAUR 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.
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.
Getting display keys to work
If the display keys (Rotate, Escape, Enter, Prev, Next,...) on your X41 tablet aren't working, add atkbd.softraw=0
as a kernel parameter in your boot loader configuration. Once they're producing scancodes, you can map them to keycodes.
External links
- This report has been listed in the Linux Laptop and Notebook Installation Survey: IBM.
- SATA support modification
- ThinkWiki X41 page
- T43p Cooling - applicable to X41t, I've added ~1mm thick copper sheet to both the CPU and northbridge heatsinks with no ill effects.
- A shell/zenity script for common X41t tasks