Apple Computer Inc.’s historic shift to Intel Corp. microprocessors came months earlier than expected Tuesday as CEO Steve Jobs unveiled desktop and notebook computers based on new two-brained chips from the world’s largest semiconductor company’s.

The first Macs to deploy Intel’s Core Duo processors will be the latest iMac desktop, whose circuitry is all built into the display, and the MacBook Pro laptop.

The new iMacs will be available with 17-inch and 20-inch screens for $1,299 and $1,699 respectively. Jobs claimed the new models are two to three times faster than the iMac G5.