Thinkpads Forum

Both machines have almost the same specifications, moreover X61 has a collection of processors more powerful than those of X61s, so why this big difference in price ?

For one reason, thinkpad X61s is smaller in size and weight i.e. it's more ultraportable, also comes with an option of UltraLight screen, uses LV (Low Voltage) processor which can easily give you battery life of around 10 hrs on 8-cell battery.

In summary, ultraportable notebooks are more expensive...

Correction: not "easily"

Most I ever got was around 9.5-10 hours reading notes with Wifi off, Minimal screen brightness, set on lowest settings.

Most times I can get 6h-6.5h if I have Wifi on, less if I'm watching films off of the HDD.

The X61s also uses a lighter design of screen which is more expensive to manufacture, which in turn does increase the price slightly.