Today at it's "We've got a little more to show you," Apple has unveiled a completely new iMac. It doesn't have a Retina display, but it does come with a new goodie Apple has cooked up called the Fusion drive.

The new iMac has a third generation Intel quad-core processors and NVIDIA graphics in the thinnest Apple all-in-one yet. One of the reasons it's so thin is that it drops the optical drive. If you want one of those you'll need to pick up an US$79 Apple SuperDrive.

Redesigned from the inside out, the new iMac packs high-performance technology into an aluminum and glass enclosure with up to 40% less volume than its predecessor and an edge that measures five mm thin, says ays Philip Schiller, Apple’s senior vice president of Worldwide Marketing.

The new iMac also features a completely reengineered display that reduces reflection by 75% while maintaining brilliant color and contrast, he adds. In the new design, the cover glass is fully laminated to the LCD and an anti-reflective coating is applied using a high-precision plasma deposition process. Every iMac display is individually calibrated using an advanced spectroradiometer.

The new iMac features third generation quad-core Intel Core i5 processors that can be upgraded to Core i7. The latest NVIDIA GeForce processors deliver up to 60% faster performance for advanced gaming and graphics intensive apps. Every new iMac now comes standard with 8GB of 1600MHz memory and a 1TB hard drive, and customers can choose to configure their iMac with up to 32GB of memory and a new 3TB hard drive, or 768GB of flash storage for ultimate performance. The all-in-one update sports two Thunderbolt and four USB 3.0 ports.

The Fusion Drive gives customers the performance of flash storage and the capacity of a hard drive. It combines 128GB of flash with a standard 1TB or 3TB hard drive to create a single storage volume that intelligently manages files to optimize read and write performance. Fusion Drive adapts to the way you use your iMac and automatically moves the files and apps you use most often to flash storage to enable faster performance and quicker access, says Schiller.

The 21.5-inch iMac is available with a 2.7GHz quad-core Intel Core i5 with Turbo Boost speeds up to 3.2GHz and NVIDIA GeForce GT 640M for a suggested retail price of $1,299; and with a 2.9GHz quad-core Intel Core i5 with Turbo Boost speeds up to 3.6GHz and NVIDIA GeForce GT 650M for a suggested retail price of $1,499 . The 21.5-inch iMac will be available in November through the Apple Online Store (www.apple.com), Apple’s retail stores and Apple Authorized Resellers.

The 27-inch iMac is available with a 2.9GHz quad-core Intel Core i5 with Turbo Boost speeds up to 3.6GHz and NVIDIA GeForce GTX 660M for a suggested retail price of $1,799; and with a 3.2GHz quad-core Intel Core i5 with Turbo Boost speeds up to 3.6GHz and NVIDIA GeForce GTX 675MX for a suggested retail price of $1,999. The 27-inch iMac will be available in December through the Apple Online Store (www.apple.com), Apple’s retail stores and Apple Authorized Resellers.