Portable speed demons who like to wring every last megahertz from their MacBooks have a new option as of Thursday as Apple has added an option for a 2.8GHz Core i7 processor to certain MacBook Pro models.

The new processor, available only as a build-to-order option on the 15-inch Core i7 MacBook Pro and the 17-inch model -- both released in April -- adds an extra bit of processing punch to the machines, which previously maxed out with a Core i7 processor running at 2.66GHz.

For those looking to upgrade, be warned that that incremental update comes with a hefty pricetag: you'll pay another £136 plus VAT to bump up from the standard Core i7 2.66GHz in the 15-inch MacBook Pro, and £272 to go from the 17-inch's standard 2.53GHz Core i5 processor to the 2.8GHz.

Of course, there are always some people who want everything they can eke out of a machine -- for them, perhaps the 2.8GHz is worth it.