There’s more than enough glitz and smartphone glamour at Mobile World Congress to keep me writing previews well into next week, but when I dropped in at the ARM stand, it was something a little unusual that drew my attention.

On the edge of a narrow bench sat a rattly-looking development unit – the kind of device phone and chip makers use to test hardware before squeezing it into the shiny, sleek chassis I’ve seen so many times over the past three days. But that’s not the interesting part: ARM was using it to demonstrate the benefits of multicore mobile processors, the sort so many of the new devices this year are set to employ.

The Texas Intruments OMAP 4 chip inside it is based on ARM’s Cortex-A9 architecture and in the video below it’s shown running Android 2.3 and Ubunutu 10.04 simultaneously.

That’s interesting from a technical point of view, you might think, but a little gimmicky right? Well, it’s closer to reality than you might think. The Motorola Atrix smartphone, launched to great fanfare at CES in January, boasts a very similar feature. Drop this in the rear of its ‘laptop’ dock and control switches to the larger screen displaying a desktop environment, allowing you to use the power of the phone just like a notebook. Motorola also has a desktop dock for the Atrix which allows you to connect it to a monitor, keyboard and mouse.

ARM also showed us a quick demonstration of how much more power the latest dual-core processors offer over their single-core counterparts. This time two bare boards, each sporting identical Nvidia Tegra 2 chips (again based on ARM’s Cortex-A9 architecture), with one running at full power and the other with one of its cores disabled, are seen rendering a sequence of locally cached web pages.

The dual-core processor streaks ahead, understandably, but it’s the margin of difference that’s the real eye-opener. Check out the video below – it’s quite revealing.

ARM envisages a time when the only computer you’ll ever need is your smartphone and with Nvidia announcing it will be putting quad-core mobile processors into tablets by autumn and smartphones by Christmas, that prospect looks to be approaching faster than anyone expected.