The new generation of iMac desktop computers is said to be up to 70% faster thanks to addition of quad-core Intel Core i5 and Core i7 processors of up to 3.4 GHz. "These next generation processors feature an integrated memory controller for an amazingly responsive experience and a powerful new media engine for high-performance video encoding and decoding," claims Apple.

The new iMac also feature the Thunderbolt I/O technology, which Apple first unveiled earlier this year in its MacBook Pro line of portable computers. Thunderbolt has been developed by Intel and enable high-speed transfers of up to 10Gbps. The 21.5-inch iMac sports one Thunderbolt port, while the 27-inch model offers two ports.

Apple has also added a new built-in FaceTime HD camera, which can be used for video calls between FaceTime-enable Macs, iPad 2, iPhone 4 and iPod Touch portable devices.

The new iMac is available in four configurations.

• The 21.5-inch iMac with a 2.5 GHz quad-core Intel Core i5, AMD Radeon HD 6750M and 500GB hard drive retailing at £999.
• The 21.5-inch iMac with a 2.7 GHz quad-core Intel Core i5, AMD Radeon HD 6770M and 1TB hard drive retailing at £1249.
• The 27-inch iMac with a 2.7 GHz quad-core Intel Core i5, AMD Radeon HD 6770M and 1TB hard drive retailing at £1399.
• The 27-inch iMac with a 3.1 GHz quad-core Intel Core i5, AMD Radeon HD 6970M and 1TB hard drive retailing at £1649.

Customers can also choose to upgrade their processors to Intel's Core i7 processors up to 3.4 GHz. Hard drive capacity can also be brought up to 2TB.

For more details, visit apple.com/uk.