Whether the first Centrino release was a response to or an effect of the rapid growth in the notebook's popularity at the time, it provided the first consensus of targeted mobile computing improvements - battery life, wireless connectivity and overall performance.

Now these feature improvements have been bolstered and added to, with, at launch, two distinct flavours of the latest Centrino. Centrino Pro targets the business user whereas Centrino Duo is for everyone else. There's talk of a Centrino Duo Extreme Edition to follow, catering for the gaming community with less emphasis on battery life and more on speed.

The perennial choice between a desktop or laptop may no longer depend on price and performance but instead on what the desktop lacks and the laptop has gained.

Turbo Memory is a case in point. The NAND flash memory hard disk enhancement technology vastly improves performance. It also promises to extend both the battery life and the life of the hard disk itself as it reduces the amount of read/write activity on the platters.

Turbo Memory is a fundamental change to data storage and the bottom line is that you will want it, especially as it will only add at most around £15 to the cost of a new Centrino laptop.

For performance improvements alone, Turbo Memory will make it onto desktop PCs at some point soon, but its effects on battery life will not be realised. And it's the overall contributions to battery life extensions that's most evident with Centrino's release.

The new GMA X3100 graphics chipset, released alongside the new Centrino, is designed with a maximum overall laptop TDP (Thermal Design Power) limitation of 35W. It achieves this with several new battery saving features including support for D2PO panel intensity dynamic adjustment as well as display refresh rate switching, which reduces the need to redraw an image on a screen when it's not moving.

However, GMA X3100 is not required for the Centrino badge, and you will find better performance elsewhere.

If battery life is a crucial factor in your choice of laptop, then along with the power-saving enhancements of the X3100 and Turbo Memory, you also have new SpeedStep enhancements.

A new processor sleep state, known as DC4, shuts down large portions of the CPU during idle periods with occasional interrupt request sweeps to see if it needs to wake up. A new lower active state allows for a change in bus clock frequency, so battery life is longer when playing DVDs and music.

We found this happening when comparing two laptops with the new platform, one sporting a Turbo Memory drive (and DC4 support), and one without; we noticed the positive difference on the fully-tooled machine, which lingered at 94 per cent battery as its opponent was 90 per cent.

The end of the line was similarly positive; the DC4-enabled machine managed an extra 16 minutes life over its otherwise identical brother.

The graphical TDP changes didn't exactly show themselves with much clarity, however. The top time on our white box systems, playing visualised MP3s in Media Player, was a mildly disappointing 137m 30s; whether commercial implementations of the mobile 965 chipset can squeeze a little more life out of the package is so far unclear.

Dynamic processor core speed changing is also used as part of the new single core Turbo Mode boosting. In all models of Core 2 Duo from 1.8GHz, one of the cores can jump in clock speed by up to 0.2GHz in response to a single application's need, and all still within the 35W TDP.