New iMacs with Quad cores and Intel thunderbolt ports

Starting at $1,199, the new iMac is up to 70 percent faster and new graphics deliver up to three times the performance of the previous generation.

"Our customers love the iMac’s aluminum enclosure, gorgeous display and all-in-one design," said Philip 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 new iMac features quad-core Intel Core i5 processors with an option for customers to choose Core i7 processors up to 3.4 GHz. These next generation processors feature an integrated memory controller for a more responsive experience and a powerful new media engine for high-performance video encoding and decoding. With new AMD Radeon HD graphics processors, Apple said the new iMac has the most powerful graphics ever in an all-in-one desktop.

iMac is the first desktop computer on the market to include Thunderbolt I/O technology. The 21.5-inch iMac has a single Thunderbolt port while the 27-inch model features two ports.

First introduced in new MacBook Pros in February, Thunderbolt is a high-speed input/output technology co-developed by Intel and Apple. Featuring two bi-directional channels, it offers speeds of up to 10Gbps, which is 12 times faster than FireWire 800, and 20 times faster than USB 2.0. It's even twice as fast as Intel's USB 3.0 specification, which the company still plans to support. Thunderbolt delivers PCI Express directly to external high performance peripherals such as RAID arrays, and can support FireWire and USB consumer devices, and Gigabit Ethernet networks via adapters.

Thunderbolt also supports DisplayPort for high resolution displays and works with existing adapters for HDMI, DVI and VGA displays. Freely available for implementation on systems, cables and devices, Apple said Thunderbolt technology is expected to be widely adopted as a new standard for high performance I/O.