Intel's newest microprocessor, the 2.2GHz version of its Pentium 4 chip, went on sale in Tokyo's Akihabara electronics district late last week, ahead of its official launch in January.

This is not just a faster version of the company's previous chips, but the first new chip to be based on Intel's Northwood core.

Produced using a state-of-the-art 0.13 micron production process rather than the 0.18 micron process used for current Willamette cores, the Northwood cores include double the previous amount of level two (L2) cache memory — now 512KB — which should translate into higher performance for users.

The Northwood core also uses less power and runs at a lower voltage — 1.5 volts, rather than Willamette's 1.75 volts.

Along with the new 2.2GHz chip, a 2GHz Pentium 4 based on the Northwood core is also due to be officially launched soon but, like the new processor, has already made its Akihabara debut, appearing a couple of days before Christmas.