Apple has announced an upgrade to its iMac PC with latest generation quad-core Intel Core i5 processors and more support for flash-memory storage.

The company has added fourth generation Intel quad-core processors, new graphics, next generation Wi-Fi and faster PCIe flash storage options to the desktop.

The 21.5-inch iMac will now be powered by 2.7GHz quad-core Intel Core i5 processor and features new Iris Pro graphics that offers better integrated graphics performance.

Apple Worldwide Marketing senior vice president Philip Schiller said that iMac continues to be the example that proves how beautiful, fast and fun a desktop computer can be.

"Inside its ultra-thin aluminium enclosure, the new iMac has the latest Intel processors, faster graphics, next generation 802.11ac Wi-Fi and faster PCIe flash storage," Schiller added.

The desktop’s high-end 21.5-inch model as well as 27-inch models are powered by 3.4GHz quad-core Intel Core i5 processors and NVIDIA GeForce 700 series graphics with double the video memory and offer about 40% faster performance compared to its predecessor.

Apple has also made the desktops available with upgrade options of quad-core Intel Core i7 processors up to 3.5GHz and NVIDIA GeForce GTX 780M series graphics with about 4GB of video memory.

Running on the OS X Mountain Lion operating system, the updated iMac offers support for PCIe-based flash storage that claimed to make Fusion Drive and all-flash storage options about 50% faster than the previous generation.