The Ultrabook has been one of the most headline-grabbing developments in notebook computing over the last few years. Even if the MacBook Air is technically not a member of this genre, it was clearly the inspiration for it, and one of its closest emulations has been Asus' delightfully metallic Zenbooks. The Prime UX32A is the latest incarnation, and whilst the chassis isn't radically different from previous Zenbooks, there are some very welcome improvements elsewhere.
The central enhancement is in the processor department, which is now the latest Intel Ivy Bridge generation. The Zenbook UX32A offers Core i5 and i7 Ivy Bridge options, but only the ultra-low voltage versions of either, and there is a Sandy Bridge-equipped budget model available in some regions. Our sample came with an Intel Core i5 3317U, which is a dual-core CPU with Hyper-Treading. The primary frequency is a reasonably healthy 1.7GHz, but Turbo Boost 2.0 can increase a single core to 2.6GHz when required. So this is a pretty capable processor when required, but otherwise miserly on power consumption.
Most significantly of all, the Ivy Bridge Core i5 comes with Intel's latest HD 4000 graphics built in, which is quite a step forward from the previous HD 3000. Not only is this a DirectX 11 GPU, but it's also nearly twice as powerful as its predecessor. All of these improvements still allow the Core i5 to achieve the same 17W draw as previous ultra-low power processors, so the extra performance comes with no hit on battery life. However, there is also a UX32VD Prime variant that includes NVIDIA GT 620M graphics for more meaty 3D acceleration, but this will have an effect on battery life.
The processor has been partnered with 4GB of 1,600MHz DDR3 memory, which is now pretty much standard, and perfectly adequate for a Windows 7 system in this class. It is possible to specify up to 6GB, but upgrading will mean swapping out the existing 2GB SODIMM for a 4GB unit (the remaining 2GB is fixed). Storage is aiming for the best of both worlds, with a 24GB SanDisk i100 solid state disk used as a cache for a 500GB Hitachi Travelstar Z5K500 mechanical hard disk. This provides the fast loading and power savings of an SSD by caching the operating system and frequently used applications on the SanDisk drive, but having the Hitachi drive available for larger storage requirements.
So, whilst the internals have made a welcome leap forward, the chassis remains quite similar to predecessors such as the UX31. That's no major issue, as this was already one of the most successful attempts at emulating the amazing design of Apple's MacBook Air. This is a very sleek and attractive system, measuring just 9mm at its widest point. The brushed metal is a bit of a fingerprint magnet, particularly the lid, but this is definitely a system that's likely to elicit admiring glances when you whip it out on the train home from work.
The 13.3in 16:9 screen has a matte finish, so isn't prone to reflections. The resolution is a reasonable 1,366 x 768 pixels, although a 1,920 x 1,080 Full HD display is also available. Viewing angles are decent, and contrast good enough for multimedia enjoyment. There's the obligatory webcam on the top edge, too, for Skype meetings or chatting to friends around the globe.
The chiclet keyboard does have quite a shallow action, which isn't surprising considering how skinny this chassis is, but it's perfectly comfortable to touch-type on for extended periods. Indeed, most of this review was written on it. It's also backlit, so you can see the keys in the dark. However, there are some issues. In particular, the large trackpad is quite easy to brush accidentally with the heel of your right hand when typing, and the buttons, which are integrated along the bottom edge, aren't as responsive as most.
We've had similar problems with non-unibody Apple MacBooks. Like the latter, the Zenbook's trackpad has been placed centrally to the chassis for aesthetic reasons, when in reality the main keys you use when typing are slightly to the left of the keyboard, so the trackpad should be as well. It's a little frustrating, but in practice won't mean you end up typing in the wrong place that often, although it does happen sometimes. The trackpad does support a useful selection of multi-touch functions, for which its large size is quite beneficial.
Another slight drawback is the lack of a built-in Gigabit Ethernet port, although a USB adapter is included, and otherwise the connectivity allocation is impressive for this chassis size. There's a single USB 3.0 and SD card reader on the left, whilst on the right can be found two more USB 3.0 ports, HDMI, an audio minijack and a mini VGA connection. Asus has helpfully supplied an adapter to turn this into a full-sized VGA port, which can still come in handy when connecting to a projector. Naturally, no optical drive is built in - this would have been next to impossible whilst maintaining the Zenbook's svelte chassis. But most of the time you won't miss it these days. There is the usual complement of wireless technologies available, including 802.11b/g/n Wi-Fi and Bluetooth 4.0, but also Intel WiDi for wireless display transmission.
Performance is decent for an Ultrabook. The Core i5 processor shows its grunt with a result of 2.4 in Maxon Cinebench R11.5's render test, which isn't up with desktop replacements such as Toshiba's Satellite L855-118, but quite a bit better than many ultraportables. The OpenGL score of 13.82 implies you wouldn't want to do any 3D graphics work on the move, even if this is streets ahead of Intel HD 3000 graphics, but 612 in 3DMark11 with Performance settings shows that a bit of gaming with low resolutions and quality settings will be possible, to idle away a journey. Asus promises more than 7 hours of battery life, and in our gruelling 100 per cent processor utilisation test it did last over two hours, so this sounds very plausible for lighter usage scenarios. In fact, if you're not using much processor or hard disk time, the UX32A seems to last a very long time indeed. Whilst you might only manage a movie or two on the plane, this laptop should give you a full journey's worth of everyday office activities. It also sits in standby for days on end without draining too much battery, coming back to life in a few seconds. This negates one of the advantages of Android-based alternatives, such as Asus's own Transformer range.
One of our favourite Ultrabooks has got even better with the UX32A. The latest Intel Ivy Bridge CPU generation packs even more processing power into the same power envelope, with a particularly significant improvement to graphics performance. The placement of the trackpad is an irritating Achilles' heel, but otherwise the Asus Prime UX32A remains one of the best alternatives to a MacBook Air, and at around £850 it's not outrageously priced, either.
Manufacturer and Product
Asus Zenbook Prime UX32A
1.7GHz Intel Core i5 3317U
4GB 1,600MHz DDR3 SDRAM
Intel HD 4000
500GB Hitachi Travelstar Z5K500 5,400rpm hard disk; 24GB SanDisk i100 solid state disk
13.3in TFT with 1,366 x 768 pixels
802.11b/g/n Wi-Fi, Bluetooth 4.0
3 x USB 3.0, SD card reader, minijack audio, mini VGA, HDMI, Gigabit Ethernet via USB adapter
Width x Depth x Height
325 x 223 x 9mm
2-years limited international