This is the most powerful iMac in Apple’s mid-2011 refresh, augmented by the 3.4GHz Intel Core i7 processor that’s available as a custom option when you order from the Apple online store. Like all the new range, the switch to cutting-edge Sandy Bridge Core i processors and powerful AMD graphics has greatly enhanced its performance, but with even the entry-level iMac matching and in some areas exceeding the most powerful model of the previous generation, does the home user really need something as powerful– and expensive – as this?

Apple iMac 27-inch: Build

The 2011 iMac retains the form factor of the previous generation, with its brushed aluminium body and edge-to-edge glass screen. Around the back, the Mini DisplayPort is replaced by two Thunderbolt ports, but the new 27-inch iMac is otherwise-identical in appearance to the 2010 release.

Apple iMac 27-inch: Screen

The screen is also unchanged, offering the same 27-inch, IPS LED-backlit widescreen glossy display (Apple still hasn’t given us a matte option, even as a custom configuration). Viewing angles are excellent; you can look at the screen from almost anywhere without the colours shifting. A 1000:1 contrast ratio gives you more vibrant colours and deeper blacks too.

Apple iMac 27-inch: Performance

With a Sandy Bridge quad-core processor, the second generation of Intel’s famous Core-i series, and an AMD Radeon HD 6970M graphics processor, this top-of-the-range iMac was bound to impress. The upgrade to the Core i7 gives it Hyper Threading, allowing each of the processor’s four cores to run two threads at a time, giving it eight virtual cores. This feature isn’t present on the Core i5 chips used in the off-the-shelf range. As a result, it scored heavily in our benchmarking tests, Doom 3 ran at an incredible 244.3 frames per second.

Apple iMac 27-inch: Connections

You’re certainly not short of connectivity options here. A generous four USB 2.0 ports are joined by a single FireWire 800 port, and most interestingly of all, two Thunderbolt ports. This new connection technology can shift data 12 times faster than FireWire 800 and over 20 times as quick as USB 2.0, and can also drive a display. As usual, all connectivity ports are around the back, which is annoying if you like a USB port on the front for flash drives or other such temporary connections.

Apple iMac 27-inch: Verdict

This top-of-the-range 27-inch iMac with a 3.4GHz Core i7 processor is an amazing machine, but far from cheap at over £1800. Those with high-end needs might well consider it worth the money, but with the sub-£1000 entry-level model in the 2011 refresh rivalling the top iMac in the 2010 range, you have to ask whether the home user really needs all that power. Professional designers and video editors will welcome its huge screen and amazing processing power, but most users would be just as happy with a cheaper iMac.

Apple iMac 27-inch price: from £1399 customisable, our version £1809, link Apple

Apple iMac 27-inch launch date: Out now