Full review
The Asus Zenbook UX31 is Asus' first foray into the ultrabook world, offering a powerful Intel Core i7 processor wrapped up in a super-slim, sturdy aluminium shell.
Asus is undoubtedly hoping to challenge Apple's dominance of the ultra-light market by offering the UX31 for £999, undercutting the similarly specced 13-inch MacBook Air by £100.
The Zenbook UX31 is available now.
Design and build quality
The Zenbook UX31 is almost identical to its smaller sibling, the UX21. They're both supremely thin, measuring only 17mm at the back and tapering down to a razor-sharp 3mm at the front, which is as slim as the MacBook Air.
The UX31, however, packs a 13.3-inch screen so its dimensions are made slightly bigger. With a width of only 325mm and a depth of 224mm, it'll happily slide into a small case without too much pushing and shoving. Apple's 13-inch MacBook Air is pretty much the same size so you can happily join in with the ultra-light crowd without feeling like a fool.
Both the 11 and 13-inch Zenbooks are machined from a single piece of aluminium, making them particularly sturdy. We grabbed the UX31 by its horns and gave it a good old squeeze. There was no flex in the chassis and it held up extremely well when we took it with us all over town for days on end. We also didn't find any bend in the lid when we opened and closed it, which helps it feel very secure and well put together.
The lid has a unique spun metal finish, which we're pretty keen on. It's a welcome change from the usual brushed metal effects found on many laptops and certainly better than plain plastic. The lid's also a slightly darker metal than the rest of the body, which adds an extra element of visual interest.
Screen
The 13.3-inch screen has a 1,600x900-pixel resolution that's sharp, clear and bright. That's the same high resolution found on the 13-inch MacBook Air. We loved how web pages and documents looked on that so we're chuffed that Asus has given us the same high quality.
Colours were handled well so if you're after a bit of BBC iPlayer and a few snatched moments with a good YouTube video it'll do the trick nicely. It didn't have the deepest black levels we've ever seen though -- especially when you have the brightness set to max -- so if you want a proper movie experience, you might want to hook it up to a big TV via the micro-HDMI port.
It's not just an HDMI port you'll find round the side; you'll also get a USB 2.0 port, a USB 3.0 port, a mini display port and a micro-HDMI port. There's also an SD card reader, which is particularly handy for quickly pulling your holiday snaps off your camera.
It's also great to see USB 3.0 here. There's a Thunderbolt port on the MacBook Air for high-speed transfers, but it's mostly designed for hooking up an external monitor. Having USB 3.0 on the Zenbook allows for nippy transfers between your laptop and an external hard disk drive.
Keyboard and trackpad
The Zenbook's keyboard looks as classy and sleek as the rest of the body, with metal-effect keys set into a darker metal surround. The keys are isolated and are set a good distance apart so your fingers aren't too bunched up when you're typing. They're not set very high though so it can sometimes be a little difficult to differentiate between each key when touch-typing at speed.
The trackpad is a large, clickable slab, much like the one you'd find on the MacBook Air. It takes up all available space so it's particularly comfy if you spend a lot of your time scrolling around all over the place. It's definitely not the most responsive of trackpads we've ever used though and two finger scrolling often sent the page jumping wildly down with only the smallest of finger movements.
It supports other multi-touch gestures such as a handy three-finger swipe upwards to take you to a cascading wheel of open windows or a swipe down to show the desktop. It's not as smooth as the multi-touch gestures on the MacBook Air, but it's great to see companies putting in more effort than the standard two-finger scroll.
Performance
The 13-inch UX31 we had our sweaty palms on was running an Intel Core i7-2677M processor running at 1.8GHz and teamed up with 4GB RAM.
We ran the PCMark05 benchmark and were given a score of 11,650, which we were particularly pleased with. The UX21 managed a score of 9,802 so you're definitely getting a bit more oomph from the meatier processor in the UX31. We saw the same when we ran the Geekbench test, on which the UX31 achieved 7,547 and the UX21 a more modest 5,828.
The UX31 is undoubtedly a very powerful machine, especially considering its supremely slim size. It's perfectly capable of chomping through playing, streaming and encoding high-definition video. It will tackle photo editing without so much as a whimper so long as you're not working with massively high-resolution raw image files.
It handled multi-tasking well with Spotify, VLC Media Player playing high-definition video and a multi-tabbed web browser all being open at once without any noticeable slowdown in performance. If you start trying to play demanding games while a video renders in the background, 4GB RAM isn't a massive amount, so you can expect the poor thing to start wailing like a puppy caught in a car door.
Annoyingly, Asus is only offering the 13-inch model with an Intel Core i7 chip. If you don't need quite so much power and opt for the Core i5 model, you'll be forced to have the smaller screen of the 11-inch UX21. It's a shame we can't customise the specifications online -- we'd love the option of having the larger screen of the 13-inch model, with the slightly reduced price that came with the i5 chip.
Asus says it wants to avoid confusing the customers by keeping the product line-up simple; each size has only one specification. It's surely not that confusing to offer two power options for each size, is it? Maybe the hive mind of CNET UK is powerful enough to make sense of these baffling specifications. Or maybe Asus is just a bit patronising.
There's no dedicated graphics card inside the UX31, but the built-in Intel HD graphics will still offer a hand with the games. We booted up Dirt 3 and revved up our trusty BMW with the Flip racing livery and sent it hurtling through the Finnish hills. With the settings ramped to the max, the UX31 only managed to churn out about 13 frames per second, which really isn't good enough for such a fast-paced game.
When we dialled the detail, shadow and resolution settings back, we managed to get around 20fps, which still isn't great but may do the job if you're really bored -- although knocking the settings down that much somewhat defeats the object of playing such a high-end game. You'd probably get a better experience out of playing the original Dirt game on higher settings.
There's a 128GB solid state drive packed inside the UX31. SSDs are smaller and faster than traditional hard disk drives, which allows the UX31 to achieve a resume-from-sleep time of around two seconds. There are no moving parts in SSDs either, so they are much more durable against knocks and bumps than HDDs as well as being more economical with power. Consequently, the Zenbook can last about a fortnight on standby.
The MacBook Air boasts a 30-day battery life on sleep mode, which beats the Zenbook by a healthy margin. We can't really think why you'd be wanting to leave your laptop sat in standby for a month though.
When we ran our battery test, the UX31 managed to last 3 hours 10 minutes, which is an excellent time. The test is hugely demanding so you'll be able to get a lot more out of it with sensible use.
It also has a handy feature of automatically saving your work when the battery drops below five per cent. That's definitely going to appeal to those of you who -- like us -- have accidentally lost work when playing the dangerous game of travelling without a battery charger.
Conclusion
The Asus Zenbook UX31 is undeniably a beautiful piece of kit. It's incredibly slim, lightweight and sturdy enough to be chucked in a bag and carted around town.
It's not just a pretty face though; this thing packs enough heat to tear through all but the most demanding of computing tasks. With a price undercutting the MacBook Air, we think Apple has finally got a worthy rival.