Apple has announced that its all-new iMac computer will go on sale this Friday (November 30), Digital Spy said.

Announced at the iPad Mini launch event last month, the new iMac comes in either 21.5-inch or 27-inch models, both with fast processors and a new storage option called Fusion Drive.

Despite rumours of delays to 2013, Apple has said that the 21.5-inch iMac will go on sale through the Apple Online Store, Apple retail stores and select Apple authorised resellers from November 30.

Online orders for the 27-inch iMac will start on the same day, and Apple said that the product will ship in December.

Billed as the "most advanced desktop Apple has ever made", the new iMacs have been redesigned "from the inside out".

The aluminum and glass enclosure measures only 5mm thick at its edge, 80% thinner than the previous model, and features a re-engineered display that is claimed to reduce reflection by 75%.

The new iMac includes 8GB of 1600 MHz memory, a 1TB hard drive and a third generation quad-core Intel Core i5 processor that can be upgraded to Core i7. It also has the latest NVIDIA GeForce graphics processors that deliver up to 60% faster performance.

Apple has fitted that iMac with what it calls Fusion Drive, a new storage option that combines a 128GB solid state drive with a standard hard drive, creating a single storage volume that intelligently manages files.