Sometimes we group laptops by price; other times by usage category. This issue, the common denominator is the processor series: Intel’s third generation of Core chips, better known as Ivy Bridge.

Internally, Intel characterises its annual evolution of products as either tick or tock – that is a die-shrink tick, such as moving from 45- to 32-nanometre (nm) transistors, or a microarchitecture tock, such as the change from Core 2 Duo to Core i5.

With Ivy Bridge Intel has retained the Core microarchitecture introduced with its 2008 Nehalem series, but shrunk last year’s 32nm Sandy Bridge chips to 22nm. As crucial to this revision is a new Tri-gate ‘3-D’ transistor that helps reduce power consumption.

See also Group test: What the best Ivy Bridge laptop?

The main processor sees some lift in performance per clock, which translates to better application performance at the same gigahertz rating. But the bigger step-up is in the integrated graphics processor, which makes a stronger case for doing without a discrete graphics chip and relying solely on this facility for onscreen action. Inspired by the larger graphics improvement over Sandy Bridge, Intel refers to this upgrade as ‘Tick-Plus’.

Ivy Bridge laptops buying advice: Core facts

The first Ivy Bridge mobile CPUs released by Intel were quad-core designs, clocked between 2.1GHz (the 3612QM) and 2.9GHz (the 3920XM). You can usually spot these quad-cores by their ‘QM’ suffix.

Quad-core processors are the most capable, and doubly so when you consider the effect of Hyper-Threading. This lets recent software operate as if it was running on an eight-core processor. The Intel parts we’ve tested here are the middle-order Core i7 chips running at 2.3GHz (3615QM) and 2.6GHz (3720QM). An added speed boost is provided by Turbo mode, which allows short-term auto-overclocking on a single core to 3.3GHz and 3.6GHz respectively.

The down side of these chips is higher power consumption and greater heat output. But even with their 45W thermal design power (TDP) we’re finding comparatively cooler and longer-running laptops than last year’s already impressive Sandy Bridge generation.

For the thin-and-light brigade, very low battery drain and minimal surplus heat are paramount. Filling that need for ultraportables are Core i5 processors with a U suffix (for ultra-low voltage), such as the 1.7GHz 3317U. This is the processor chosen by Apple for its MacBook Air and Samsung for its Series 9.

Between the fastest quad-core Core i7 and the most frugal Core i5 ‘U’ series is a range of dual-core chips. The Dell Inspiron 15R, for example, takes a 2.5GHz Core i5-3210M.

Note the names Intel uses to market its processors, where a Core i7 can be a quad- or dual-core chip, while Core i5 for mobile are always dual-core. Unlike earlier generations, all i5 and i7 chips include Turbo and Hyper-Threading. There is now only one Core i3 listed by Intel, the 1.8GHz 3217U, which omits Turbo mode.

Any Ivy Bridge processor will unlock terrific speed and great battery economy. If your needs include video editing, virtualisation or workstation activities, you’ll likely benefit from a QM version.

Intel Ivy Bridge laptops buying advice

Ivy Bridge laptops buying advice: Conclusion

Gaming enthusiasts will be well served by the Alienware M14x, a smart and sturdy 14in laptop with plenty of raw power in Windows and games. Hooked up to an external monitor, its nVidia graphics processor should allow detailed rendering on a larger screen.

We weren’t convinced by the Toshiba Qosmio X870-11Q. It has all the bells and whistles necessary to entice a spec-checking buyer, along with the gaudy finish of a boy-racer machine, Blu-ray and 3D playback, but it’s expensive, poorly built and has a short runtime.

Dell’s Inspiron 15R is another plasticky affair, with several cost-cutting measures on display. It’s by far the cheapest Ivy Bridge laptop here, though, at just £579.

Whereas most rivals to the MacBook Air are building 11- and 13in Ultrabooks, Samsung hit the Enlarge button for the 15in Series 9.

It’s remarkably similar to the Air, but offers a decent 15.6in widescreen and has a darker anodised finish across its metal jacket.

Two MacBooks feature in this group: the cheapest and most expensive models in Apple’s catalogue.

The £849 MacBook Air delivers on what the netbook only promised – a fast booting, speedy, lightweight and extremely portable laptop. The most affordable model packs only 64GB of storage, but new USB 3.0 ports ease the addition of external storage.

The MacBook Pro Retina will spearhead a revolution in high-res displays for personal computing. Apple’s use of IPS technology should raise the game for competitors to improve their own screens. With the help of Intel’s 2.6GHz Ivy Bridge chip, plenty of memory and a fast GPU and SSD, it’s also the fastest laptop around.