When it comes to Apple's product portfolio, the iMac range often doesn't get the same kind of attention as popular "it" products like the iPhone 4, iPad, or MacBook Air. However, Apple still relies quite heavily on its iMac family and today announced a top to bottom refresh complete with new Sandy Bridge processors and Thunderbolt I/O technology.

First off, all members of the iMac family now feature Intel's latest quad-core processors, with the low-end models getting the Core i5. Core i7 processors are a standalone option for the 21.5" and 27" iMacs. 

Apple loves to play the numbers game whenever it refreshes its product lines, and the latest iMacs are no exception. The company says that the new iMacs are up to 70 percent faster in overall performance and that graphics performance is up to three times faster than before.

The other big addition to the iMac family is the Thunderbolt I/O technology that was first introduced on refreshed MacBook Pros earlier this year. Thunderbolt provides two bi-directional data channels and transfer speeds of up to 10Gbps. Apple's 21.5" iMacs feature one Thunderbolt port while the 27" iMacs get two ports.

“Our customers love the iMac’s aluminum enclosure, gorgeous display and all-in-one design,” said Phil Schiller, Apple’s senior vice president of Worldwide Product Marketing. “With next generation quad-core processors, powerful new graphics, Thunderbolt technology and a FaceTime HD camera, we've made the world’s best desktop even better.” 

The base 21.5" iMac starts at $1,199 and comes with a 2.5GHz Core i5 processor, AMD Radeon HD 6750M GPU, and a 500GB HDD. The base 27" iMac starts at $1,699 and comes equipped with a 2.7GHz Core i5 processor, AMD Radeon HD 6770M GPU, and a 1TB HDD.