PREMIUM
As a premium buyer, money is - almost - no object. You want top performance, and you want it now. When you start spending this kind of cash, the market splits into two clear divisions: ultra-portables and desktop replacements.

Premium ultra-portables
As a premium buyer, you'll be disappointed to hear that spending more on your ultra-portable doesn't necessarily get you increased performance over the cheaper mainstream models. Instead, you get a complete physical redesign into a chassis designed to evoke awe and wonder in all who see it.

The premium ultra-portable market is currently dominated by two models - Dell's Adamo XPS and Apple's MacBook Air - though the recently reviewed Samsung 900X3A gives them a run for thei money. Both market leaders are thin enough to almost disappear when viewed side-on, and both will set you back a significant amount of money.

Samsung's 900X3A is a new entrant to the premium ultra-portable class.

The overwhelming majority of premium ultra-portables ditch mechanical hard drives and integrated optical drives for reasons of space, using optional USB-connected optical drives and solid-state storage devices instead. SSDs bring major improvements, including silent operation, lower power draw, and faster load times, but generally offer significantly less capacity than mechanical hard drives - you can expect to get 256GB as an absolute maximum from a laptop with an SSD, and you'll be paying a serious premium for that.

Desktop replacements
If portability isn't your major requirement, the other end of the premium market is in desktop replacements. Featuring large displays - 17in or even 19in - and powerful processors, they offer the ultimate in performance for high-end professional or gaming use.

The large chassis of desktop replacements enable them to pack in impressive sound systems, usually with Dolby and sometimes even THX certification, and couple it with impressively powerful graphics chips from AMD or Nvidia. Some even allow two graphics chips to be added to a single laptop, using CrossFireX or SLI to boost performance still further.

Performance, however, still lags behind that of true desktop systems: it's just not possible create a mobile graphics chip that can have the same bulky cooling system as a desktop graphics card, meaning the specifications have to be toned down. Laptops are also difficult - if not near-impossible in some cases - to upgrade, so be careful if you're buying a desktop replacement as a gaming machine.

Desktop replacement laptops like Dell's XPS 17 offer high performance, but are still no match for the fastest desktop systems.

Whichever you buy, you can expect to spend £1,300 and upwards - with features such as large SSDs and multiple graphics chips causing the price to increase rapidly.

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