ThinkPad X40 – IBM’s first ultralight X-Pad restored

Let’s take a look at the IBM ThinkPad X40 – IBM’s first ultralight X-Pad.

The X-line is distinctively small at 12” but still powerful – the international business machines became fully mobile. The X40 was ultralight, a technical marvel in its time. Check out the video review for more information!

This is the slightly adjusted script of the video above.

Let’s compare it to a 15” T43 from that same generation – what a difference in size and weight. We have the old IBM Logo twice and no sign of Lenovo yet.

Size comparison X40 vs. T43p from the same generation

Take a look at this X-generation: all of them have Pentium-M CPUs. The X40 should have been called the X31s because it was sold at the same time as the X31 and X32 which had similar technology inside but were heavier machines.

The technical specs were good in its time. This one is from 2005, has a single core Pentium-M 1.5 GHz with 1.5 GB RAM and Intel graphics.

ThinkPad X40 X41 X31 X32 compared
Pentium-M X-Pad generation compared

The X40 has some distinctive features compared to the contemporary X32. It was of course ultralight, it had a 1.8” mini-hard disk and we got an SD-Card reader. The battery is removable from the backside. The smaller form factor mandated some compromises like the removal of the parallel port and only one RAM slot.

Let’s take a look at the ports. The left side has power 16V, VGA, USB2 plus a nonstandard power port to support external optical drives and fan exhaust. The right side has CardBus, microphone and headphone, SD-Card and infrared, another USB2 port, Ethernet and modem and Kensington lock.

The back side has nothing except for the battery. The front has a single screen latch and the hard disk bay cover underneath.

The dock connector allows for a docking station with additional ports like serial, parallel and PS/2 and of course an inbuilt optical drive. Fun fact: you have to press this button to prepare undocking or you will get an alarm if you just try to remove it.

ThinkPad X40 docked
ThinkPad X40 docked

There was quite a range of CPUs available but all of them are single core Pentium-M which are still capable of running most single applications but not very fast.


There is only one graphic card available: the Intel Extreme Graphics 2, a lower-end card with no video acceleration or any modern feature but at least it runs quite cool.

There is also only one display available: a 4:3 TN panel 12″ 1024×768 (XGA), actually quite good for its time, we have decent viewing angles and nice colors.

ThinkPad X40 T430s compared
Display compared to a more modern T430s

The keyboard feels great and old-school with tactile feedback and long key-travel with a sturdy base. We have dedicated volume and speaker mute buttons as well. Compare the old layout to a modern ThinkPad here. TrackPads do not exist at all in this generation.

ThinkPad X40 T430s keyboard compared
Old vs modern keyboard layout

There are two kinds of battery, the extended 9 cell that we have here and the smaller 6 cell battery that fits flush.
Let’s start the restoration. First step is polishing like I always do, looks nice again!

There is a small flap on the underside for a single DDR1 RAM stick in combination with onboard RAM so we are upgraded to the maximum of 1.5 GB.

  • MAX 1GB DDR (PC-2700) + 250MB OR 500MB ONBOARD RAM

A mini-PCI slot comes with a WiFi card. We have an additional small connector for a modem card or optional as a Bluetooth+modem combo.

  • mPCI SLOT with a WIFI-CARD

Now talk about the hard drive and we have two problems here. First one is the old PATA connector and second is that 1.8” mini form factor. The old drive is still working but it is slow and loud. Fortunately IDE-to-mSATA adapters are available for low cost so I could install a modern mSATA SSD here and it worked just fine.

ThinkPad X40 IDE msata adpter
IDE-mSATA adapter and a mSATA SSD installed

Next step is replacing the old TrackPoint with a new classic dome. You can change the old BIOS battery below the keyboard. Cleaning the fan and changing CPU paste is quite difficult because you have to take apart nearly everything. The X40 does have good fan behavior in particular if you install the tpfancontrol software. It runs quite silent now.

The original operating system was Windows XP and we still have that sticker. I have Windows 7 running and it is fine expect there are no drivers for the video card so games do not run at all. You can also run Linux from a USB stick which should run fine here.

The X40 is still as light as a modern ThinkPad X280 and has many old-school features. We have full key travel, one RAM slot, narrow screen bezels, full Ethernet port and a removable battery. Take note Lenovo!

Thanks for reading! You can check out more of this blog or my YouTube channel.


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