Asus ZenBook UX31 review

The ultra-portable laptop market has been all but dominated by the Apple MacBook Air for the past few years, but Intel’s Ultrabook specification looks set to turn things around for Windows-based machines. If this Asus ZenBook UX31 is any indication, Apple now has some serious competition.

Of all the Ultrabooks we’ve previewed so far, including the Acer Aspire S3 Ultrabook and the Toshiba Z830 Ultrabook, it was the Asus ZenBook UX21 and UX31 models that really wowed us.

Weighing an incredibly light 1.3kg and only 17mm thick at its widest point, the Asus ZenBook UX31 is an amazingly compact laptop. A tapered design means the thinnest edge is a miniscule 3mm, which matches the tiny dimensions of the 13in MacBook Air. The brushed aluminium chassis is sleek and refined, but also incredibly strong – the lid refused to buckle under pressure and we couldn’t spot any flex in the keyboard tray.

The full-size QWERTY keyboard was excellent to type on, thanks to its isolated keys that were well spaced. Despite having very little travel, each key felt springy and responsive, so we could type at full speed right away. Below it, Asus has managed to squeeze in a large brushed metal touchpad – both the pad and its buttons are machined from a single piece of aluminium, but it has none of the problems of other all-in-one touchpads we’ve seen as pressing the buttons doesn’t jog the mouse cursor. With minimal friction and responsive buttons, we could easily navigate the Windows desktop without any trouble.

With space at a premium, Asus has used micro-HDMI and mini-VGA video outputs; plus there’s a multi-format memory card reader, two USB ports and a combination audio jack. We were slightly disappointed that only one of the two USB ports supports the faster USB3 standard, but at least the cleverly designed power adaptor doesn’t block that port when it’s plugged in to the mains.

In spite of its size, Asus has still managed to fill the ZenBook UX31 with some high performance hardware, including an ultra-low voltage version of Intel’s excellent Core i7 processor. The dual-core i7-2677M normally runs at 1.8GHz, but can Turbo Boost up to 2.9GHz when extra power is needed. Paired with 4GB of RAM and a super-fast 128GB SATA III SSD, it flew through our benchmarks with an overall score of 47. This might not make it a match for desktop machines, but frequent travellers will have more than enough power for almost every task.

By comparison the 13-inch Apple MacBook Air (Mid 2011) only scored 43 in the same benchmark.

Unsurprisingly given its slim chassis, Asus hasn’t been able to add a dedicated graphics card to the UX31 – instead, it uses the graphics chip integrated into Intel’s processor, which is easily powerful enough to play high definition video. We could watch 720p video on the laptop, or 1080p files on an external display, but it isn’t well suited to modern games. It managed just 14.5fps in Dirt3, which means you’ll have to drop the detail settings right down to play new titles, although older games will fare better.

Everything we watched on the 13.3in display looked fantastic, thanks to its field-leading 1,600×900 resolution. The Asus ZenBook UX31 is the only UltraBook with this resolution, giving it a big advantage over the competition – the 13in MacBook Air has a 1,440×900 display. Text looked sharp without appearing too small, images were highly detailed and colours were accurate even at full brightness. Contrast was also excellent, letting us pick out details in our darker test files. Viewing angles were about average, and the glossy screen finish makes it difficult to avoid light reflections, though its wide range of movement does help compensate for this.

We were expecting great sound quality to match the fantastic image, as Asus has teamed up with experts Bang and Olufsen for the ZenBook’s speakers, which are embedded in the screen hinge. Although they were no match for a dedicated speaker system, we were very impressed with both volume and frequency range – very high-end notes crackled slightly and bass was minimal, but most tracks sounded clear and warm.

Despite the powerful components inside, the UX31 still managed a superb seven hours in our light-use battery test. As long as you stick to light tasks such as web browsing and word processing, you should be able to go most of a working day without having to reach for the charger. An Instant On feature resumes from sleep mode in less than two seconds, which makes it ideal for stop-start working on the move. Asus claims that the ZenBook will hold its charge for two weeks, which falls short of Apple’s one month claim for the MacBook Air.

As other UItraBooks have yet to go on sale in the UK, the Asus ZenBook UX31 currently has only one real competitor – the MacBook Air itself. However, the UX31 has a better specification, with its faster processor and higher resolution screen, and is more keenly priced, too. Its RRP is £100 cheaper than the equivalent 13in MacBook Air, and at retail you should save even more. It lacks a backlit keyboard, but otherwise matches the Air in terms of styling, battery life and portability. The Air has the Thunderbolt I/O port plus the option of a larger 256GB SSD – although for an eye-watering extra £250 – neither of which is likely to tempt most buyers.

Because it’s the first UltraBook we’ve reviewed, it’s impossible to say whether the Asus ZenBook UX31 will be bested by a competitor over the next few months. However, based on what we’ve seen, it’s going to be incredibly difficult to beat – the fantastic design, sturdy build quality and excellent performance make the UX31 an incredibly desirable machine. If you’ve been waiting for a Windows MacBook Air equivalent, then that wait is over.