XLR8 is offering 550MHz processor-upgrades for owners of Sawtooth-based Power Mac G4s - these Macs were released in 1999 at 350MHz and 400MHz. Available speeds till now included 350MHz, 400MHz, 450MHz and 500MHz.

The upgrade yields a speed fillip without changing the rest of the Mac’s hardware – it increases performance by up to 55 per cent, claims XLR8.

To get the upgrade, Sawtooth owners must place orders on XLR8’s Web site, and select either the Standard or Advanced Upgrade option.

Choices, choices The Standard Option, which costs $299 (about £204), asks users to remove the Mac’s processor card and send it to XLR8, who will then upgrade it to 550MHz, and ship the unit back.

The Advanced Option requires users to pay a $299 deposit, and an additional $299 for the upgrade. XLR8 sends a 550MHz processor card for the customer to swap. Upon returning the old processor-card, the $299 deposit is returned to the customer.

Customers receive either a processor removal kit or a complete processor-upgrade kit, depending on the upgrade option chosen. Instructions with diagrams are supplied with both options. Upgrades carry a two-year warranty.