Asus Zenbook UX31A

The Asus Zenbook was one of the first entrants in the new ultrabook category when it launched in late 2011. We liked that original system, despite a few serious flaws, and the all-metal design marked it as a direct competitor to the MacBook Air.

Since then, ultrabooks have become both more common and less expensive. Asus now makes several UX variations, including three that we are reviewing, the UX31A, UX32A, and UX32VD. For $1,079, the Zenbook UX31A is neither the most nor least expensive of the current crop, but it is slightly thinner than the other two models.

For three systems that look so similar, there are a lot of differences between them. The 13-inch Asus Zenbook UX32VD comes alluringly close to being an ultrabook without compromise. For $1,299 it includes an Intel Core i7 CPU, a full HD 1,920x1,080-pixel-resolution display, and a discrete Nvida 620M GPU.

The UX32A still has a previous-generation Intel Core i3 CPU. That generation of chip is known by the code name Sandy Bridge, while the latest generation is Ivy Bridge. The Zenbook with the older CPU is slower, and also loses out on new Intel improvements, most notably the new HD 4000 integrated graphics.

Falling between those two extremes is this system, the UX31A. It's a more upscale design variant with a thinner chassis. It skips the GPU of the thicker UX32VD, but keeps the high-res screen and Ivy Bridge internal hardware. But at about $1,079, it doesn't make the most compelling value case. Many ultrabooks with Ivy Bridge components and solid-state drive (SSD) storage are available for around $800 or $900, and the UX31A does nothing in particular to justify a $200-$300 premium. That said, it's still one of the nicer-looking ultrabooks around.

Asus Zenbook models compared

	CPU	GPU	Storage	Display	Price
UX32VD	1.7GHz Core i7-3517U	Nvidia GeForce 620M	500GB HDD/24GB SSD	1,920x1,080	$1,299
UX32A	1.4GHz Intel i3-2367M	Intel HD 3000	320GB HDD/32GB SSD	1,333x768	$779
UX31A	1.7GHz Intel Core i5-3317U	Intel HD 4000	128GB SSD	1,920x1,080	$1,079

Asus Zenbook Prime UX31A specs

Price as reviewed	$1,079
Processor	1.7GHz Core i5-3317U
Memory	4GB, 1,600MHz DDR3
Hard drive	128 SSD
Chipset	Intel QS67
Graphics	Nvidia GeForce GT 620M / Intel HD4000
Operating system	Windows 7 Home Premium (64-bit)
Dimensions (WD)	12.8x8.8 inches
Height	0.1 - 0.7 inch
Screen size (diagonal)	13.3 inches
System weight / Weight with AC adapter	3.1 pounds / 3.5 pounds
Category	13-inch

The Zenbook line launched in late 2011 and its design -- aluminum, tapered, and minimalist -- made it the most Air-like of the early ultrabooks, at least until the Dell XPS 13 came around. But it also had a few design miscues. The lid on the original Zenbook was notoriously hard to open. That's been fixed here, across all three new Zenbook models we've reviewed.

The UX31A shares the more tapered design of the original Zenbook. It's slightly thinner and lighter than the UX32A and UX32VD models, although all three have a sharp front lip that can be murder on the heels of your hands, depending on your typing style. Despite the similarities, the small difference in thickness and weight in the UX31A actually feels pretty significant in the hand -- this is the closest to the ultrabook ideal.

The keyboard was a weak point on the original Zenbook, with shallow, clacky keys. The UX31A, with the same thin body, has similar shallow keys. For a better typing experience, check out the other two slightly thicker and heavier Zenbooks. The extra depth on those lets the keyboard have a little more space. Even though the keys here are shallow (a problem on other thin ultrabooks, such as the Sony Vaio T), the keyboard is thankfully backlit, a must-have feature on any ultrabook.

The large but finicky clickpad on the first UX31 was one of our main problems. Thanks to updated driver software from Asus, this feels like a reasonable improvement. It still gets a bit jumpy sometimes, and is under-responsive at other times.

There is, however, a decent set of multitouch gestures, demoed and controlled by the Asus Smart Gesture software app. It's nowhere near as intuitive or responsive as a MacBook trackpad, but that's a Windows-wide problem. One nice touch -- you can set a two-finger tap to indicate a right-click, a very Mac-like move that I've seen popping up a few Windows laptops lately.

In another change from the previous generation of Zenbook laptops, the display is now full HD, with a 1,920x1,080-pixel native resolution. That will be a major selling point to some for playing 1080p video content, but it can make text very small and hard to read at times. The UX32VD model also has a 1080p screen, while the less expensive UX32A has a 1,366x768-pixel screen.

Audio through a speaker grille at the very top of the keyboard tray was predictably thin, despite the Bang & Olufsen ICE Power branding. Audio volume controls are mapped to alternate F-key functions, so you'll need to hit, for example, Fn+F10 to mute the sound.

	Asus Zenbook UX31A	Average for category [13-inch]
Video	HDMI (via dongle), VGA (via dongle)	HDMI or DisplayPort
Audio	Stereo speakers, headphone jack	Stereo speakers, headphone/microphone jacks
Data	2 USB 3.0, SD card slot	2 USB 3.0, 1 USB 2.0, SD card reader
Networking	Ethernet via dongle, 802.11n Wi-Fi, Bluetooth	Ethernet, 802.11n Wi-Fi, Bluetooth, optional mobile broadband
Optical drive	None	DVD burner

Compared with the thicker UX32 model Zenbooks, you lose a USB port here, but little else, even with the thinner body. The USB 3.0 ports even charge devices (like phones and media players) while the system is asleep or off.

One important aspect of this latest generation of Zenbook laptops is the jump to Intel's third-generation Core i-series processors. But not all the current Zenbooks have that, nor do they have similar storage or graphics hardware. The $1,299 UX32VD has a 1.7GHz Intel Core i7-3517U along with a 500GB HDD/24GB SSD combo drive, and Nvidia GeForce 620M graphics. The $779 UX32A has a previous-generation 1.4GHz Intel i3-2367M CPU, 320GB HDD/24GB SSD, and Intel HD 3000 graphics. Finally, this model, the $1,079 UX31A, has a 1.7GHz Intel Core i5-3317U CPU, 128GB SSD, and Intel HD 4000 graphics, plus a slightly thinner body.

Of those three, the UX32VD is the most expensive, but also much faster at running our benchmark tests, beating out the other two Zenbooks, but falling behind an Intel Core i5 MacBook Air. In everyday use, I found all three to be more than responsive enough for common computer tasks, from social networking, to working in Microsoft Office, to running Photoshop. That said, there's a significant performance gap between this and the UX32A, with its older Sandy Bridge CPU. That makes this Ivy Bridge Core i5 the perfect middle-of-the-road choice, and indeed, it's what you'll find in most midprice ultrabooks.

The default Intel HD 4000 integrated graphics in the UX32A ran our very forgiving Street Fighter IV test at the system's very high 1,920x1,080 resolution at 16.3 frames per second. That's not great, but knock it down to a lower resolution (such as 1,600x900) and you'll do OK in games like Street Fighter IV or Portal 2. If you're at all interested in better ultrabook gaming, the UX32VD is the Zenbook for you, as it has an Nvidia GeForce 620M GPU.

All three of the Asus Zenbook models we tested had solid battery life, to varying degrees. The UX31A ran for 6 hours and 16 minutes in our video-playback battery drain test. That's excellent, but still more than an hour behind a 13-inch MacBook Air. In comparison, the UX32A ran for 5 hours and 16 minutes -- decent if not spectacular. The UX32VD has higher-end components, but still ran for 5 hours and 13 minutes.

Asus offers a one-year mail-in warranty on each of these ultrabooks, which includes accidental damage protection, and a 30-day no-dead-pixel guarantee (which is rare). The Asus Web site can get a little confusing to navigate, but 24-7 phone support is available at 888-678-3688. The simplest way to find the Asus support section for your specific model is to ignore the frustrating pop-up navigation menus and simply type the model number into the support page search box.

The Asus Zenbook UX31A is the best-looking and most compact of the current batch of 13-inch Asus ultrabooks. Unfortunately, there are plenty of systems with the same components and reasonably similar designs for under $1,000, making this a tough sell from a value perspective.

Find out more about how we test laptops.

System configurations:

Asus Zenbook Prime UX31A
Windows 7 Home Premium (64-bit) w/ SP1; 1.7GHz Intel Core i5-3317U; 4GB DDR3 SDRAM 1,600MHz; 64MB (Dedicated) Intel HD 4000; 128GB Adata XM11 SSD

Asus Zenbook Prime UX32A
Windows 7 Home Premium (64-bit) w/ SP1; 1.4GHz Intel Core i3-2367M; 4GB DDR3 SDRAM 1,333MHz; 64MB (Dedicated) Intel HD 4000; 320GB Hitachi 5,400rpm

Acer Aspire S5-391-9880
Windows 7 Home Premium (64-bit) w/ SP1; 1.7GHz Intel Core i5-3317U; 4GB DDR3 SDRAM 1,333MHz; 128MB (Dedicated) Intel HD 4000; 256GB Lite-On IT SSD (2x RAID 0)

Asus Zenbook Prime UX32VD
Windows 7 Home Premium (64-bit) w/ SP1; 1.9GHz Intel Core i7-3517U; 4GB DDR3 SDRAM 1,333MHz; 1GB Nvidia GeForce GT 620M / 64MB (Dedicated) Intel HD 4000; 500GB Hitachi 5,400rpm

Apple MacBook Air 13.3-inch (Summer 2012)
OS X 10.7.4 Lion; 1.8GHz Intel Core i5; 4GB DDR3 SDRAM 1,600MHz; 384MB (Shared) Intel HD 4000; 128GB Apple SSD