ASUS Zenbook Prime UX21A preview

More Info

It was only a matter of time before ASUS refreshed its line of Ultrabooks with Intel's new Ivy Bridge chips, but the truth is, the company needed to improve a little more than just the CPU model number. If you recall, the Zenbook UX31 ushered in a modern metal design and unbeatable speed, but our enthusiasm waned after spending a week with the flat keyboard and temperamental touchpad.

Well, friends, it looks like Chairman Jonney Shih and co. were listening: the outfit is about to bring four of its leaked Zenbook Prime laptops to the US. These include the 11-inch UX21A, which you see up there, along with the 13-inch UX31A, UX32A and the UX32VD -- essentially, the UX31A with discrete graphics. Though different configurations are bound to vary, they all bring retooled, backlit keyboards, refined trackpads and, of course, Intel's third-generation Core processors. And while the lower-end UX32A is stuck with 1366 x 768 resolution, every other model -- yes, even the tiny UX21A -- will be offered with a 1080p IPS display.

In general, ASUS isn't ready to talk availability for these four models, and has not given any indication as to how much the UX21A will cost (it did reveal tentative prices for the other three). So these aren't shipping products you can buy just yet, but luckily for us, we got the chance to spend a few days with the UX21A. While we're holding off on calling this a review -- we need a price and final, production-quality unit for that -- we're good and ready to share our early thoughts. So what are you waiting for? Meet us past the break where photos, benchmark scores and detailed impressions lie in waiting.

Look and feel

Looking at the UX21A, it's obvious that ASUS was reluctant to change the design: it altered only the things customers had been complaining about, which is to say the keyboard deck has gotten a substantial makeover. But otherwise, it's the same aesthetic. And why not? The spun metal lid was striking enough the first time, as was the all-metal chassis, pinch-thin silhouette and smooth, closed-door bottom. If you're an obsessive like some of us, you might notice the spun pattern seems finer, and that the edges feel slightly softer. ASUS also removed the tacky script branding that we took issue with on the original. Those tweaks minor enough for you?

At 2.4 pounds and 9mm thick at its plumpest, the UX21A is light: on par with other 11-inch laptops, including the MacBook Air. As you'd expect, it's easy to hold in one hand, and even easier to slip into a shoulder bag, but working with it on your legs can take practice. Mostly, that's because the weight distribution is lopsided enough that the dense, metal-backed lid causes the whole machine to tilt back precariously (read our IRL column and you'll see some 11-inch Air owners have the same beef). In any case, it's easy enough to avoid this by making sure not to tilt the screen too far away from you, which shouldn't be a problem, given that versatile IPS display and all.

As ever, this kind of skinniness comes at a cost: the UX21A only makes room for a handful of ports, including two USB 3.0 sockets, a headphone jack, mini-VGA and micro-HDMI. That's right, there's still no SD reader on this little guy; you'll have to step up to one of the two 13-inch models for that. Other than that, there aren't any differences between the two sizes.

Wrapping up our tour, the lot have sealed bottoms, which means the battery, memory slots and SSDs aren't user-replaceable. Each has 802.11a/b/g/n WiFi along with Bluetooth 2.1 + EDR. You'll also get support for both Bluetooth 4.0, as well as 10/100Mbps Ethernet, so long as you supply an external cable. Finally, this thing's got Intel Wireless Display on board for streaming 1080p video to a high-def monitor or TV.


You didn't think ASUS would have a change of heart when it came to accessories, did you? As with the first-gen Zenbooks, the company's throwing in a sleeve (this time in a muted brown), along with mini-VGA-to-VGA and USB-to-Ethernet adapters. You're on your own for full-sized HDMI. As for the power adapter, it's a small, boxy affair with a thin, non-removable cord on one end, and an outlet connector that can be detached -- not unlike Apple's power bricks.

Keyboard and trackpad

If our review of the original Zenbook boiled down to "It's great, but...," that potential deal-breaker could have been the lifeless keyboard, flaky trackpad or both, depending on how sensitive you are to such things. ASUS clearly took these criticisms to heart, if this specimen we have before us is any indication. With this generation, the outfit's traded those flat, metal keys for something cushier, with deeper pitch and a little more bounce -- a 12 percent boost in travel, says ASUS.

It's a classic case of function over form, really: while the black, plastic keys don't look as futuristic as the ones they replace, they're worlds more comfortable to type on -- even on the 11-inch model, which naturally makes do with less deck space than the 13-incher. Ultimately, yours truly wrote the brunt of this preview on the Prime, with only a few instances of keys not registering presses. We only wish it were such smooth sailing for people who took a chance on the original models.

Another complaint ASUS heeded was the lack of keyboard backlighting on the first Zenbooks. This go-round, there's a white glow emanating from beneath the keys. Unlike, say, Samsung's Series 9, which is hardwired to shut down the backlight in bright-enough environments, you can turn these lights on or off whenever you want. You can't manually adjust the level of brightness, but, then again, there's already an ambient light sensor doing those calculations for you. There are two function keys dedicated to enabling or disabling the backlighting, and while you're poking around that top row, you'll also find volume, brightness and mute controls, among others. If you're curious, these functions are all secondary, meaning you'll need to press the "Fn" button to make use of them.

And though we haven't yet had a chance to test a final, production-grade version, it would seem that ASUS managed not to repeat the mistakes it made with the first gen's touchpad. This time around, navigation is reliable and precise -- not once did the cursor jump to random parts of the screen as we were typing. It also responds impeccably to multitouch gestures, with smooth two-finger scrolls and some of the most controlled pinch-to-zoom we've ever experienced on a Windows PC. To wit, this is one carefully machined clickpad; the button is quiet and easy to press, without feeling too stiff or gummy.

Display and sound

So you pressed "Ctrl-F" looking for "1366 x 768" and turned up nothing. (Except that little bit there.) Now what are you going to complain about? Not the display, anyway. As it was, the 13-inch Zenbook UX31 was remarkable for offering 1600 x 900 resolution, but now ASUS is upping the ante, moving to a 1080p pixel count on both its 11- and 13-inch models. What's more, this isn't just your garden-variety TN panel, but an IPS display offering 350-nit brightness, 72 percent color gamut and 170-degree viewing angles (yours truly misspoke in that video up there and said 178 degrees; that's not correct).

No surprise here: 1080p is plenty dense on an 11-inch display, and we actually found ourselves zooming in on pages packed with text. What really spoiled us, though, is the quality of the screen. It's just saturated and glossy enough that it brings out the best in movies, but you might still mistake it for a matte display at first glance; there's that little glare to put up with. As you can hopefully see in our hands-on shots, the viewing angles are wide, as promised, and images hold up well whether you watch from the side or with the screen dipped at an acute angle.

Something ASUS didn't need to fix? The speakers. Even its first-generation Ultrabooks offered alarmingly loud, robust sound, thanks to a slamming Bang & Olufsen setup. Those speakers live on here (albeit, with minor tweaks), and so does the superior sound quality.

Performance and battery life

ASUS Zenbook UX21A



Dell XPS 13 (1.6GHz Core i5-2467M, Intel HD Graphics 3000)



HP Folio 13 (1.6GHz Core i5-2467M, Intel HD Graphics 3000)



Toshiba Portege Z835 (1.4GHz Core i3-2367M, Intel HD Graphics 3000)



Lenovo IdeaPad U300s (1.8GHz Core i7-2677M, Intel HD Graphics 3000)



ASUS Zenbook UX31 (1.7GHz Core i5-2557M, Intel HD Graphics 3000)



Acer Aspire S3 (1.6GHz Core i5-2467M, Intel HD Graphics 3000)



13-inch, 2011 MacBook Air (1.7GHz Core i5-2557M, Intel HD Graphics 3000)



2011 Samsung Series 9 (1.7GHz Core i5-2537M, Intel HD Graphics 3000)



Note: the higher the score the better.

Since Intel hasn't announced the remainder of its Ivy Bridge CPUs, ASUS isn't yet discussing the clock speed or model number of the processors it's used. (We could tell you ourselves, but we'd be breaching a confidentiality agreement. Sorry, Charlies.) What we can share is that this particular UX21A runs off a third-generation Intel Core processor, paired with 4GB of RAM and a 256GB SanDisk 6Gbps SSD (128GB drives will also be available). Oh, and cheer up, folks, because while we can't disclose the exact CPU just yet, we were allowed to benchmark the snot out of our test machine. As you can see in the table above, it steamrolls most Ultrabooks and just about matches the last-gen UX31. Interestingly, the UX21A notches a clear lead in the graphics department, which lends credence to rumblings we've heard about Intel's newest integrated solution offering a nice boost over the ol' HD 3000.

In everyday use, too, it aims to please: our test unit routinely booted in about 18 seconds and resumed from sleep in less than two. In the disk benchmark ATTO, its read speeds peaked at 486 MB/s while its writes maxed out at 356 MB/s. That's not quite as fast as the SATA III inside the UX31, but it easily tops the SSDs inside most of the Ultrabooks we've reviewed.

ASUS Zenbook UX21A


15-inch Samsung Series 9 (2012)


HP Folio 13


Toshiba Portege Z835


ASUS Zenbook UX31


13-inch, 2011 MacBook Air

5:32 (Mac OS X) / 4:12 (Windows)

HP Envy 14 Spectre


Lenovo IdeaPad U300s


14-inch Samsung Series 5 Ultrabook


Dell XPS 13


Samsung Series 9 (2011)


Acer Aspire S3


The 11-inch UX21A we tested has a 35Wh (4,800 mAh) battery, while the two 13-inch models make room for a 50Wh (6,840mAh) cell. Unsurprisingly, then, it doesn't come close to matching some of the larger, more longevous models we've tested. All told, it lasted four hours and 19 minutes in our battery rundown test, which consists of looping a movie off the local disk with WiFi on and the brightness fixed at 65 percent. According to ASUS' engineering team, the UX21A is capable of around five and a half hours with more mixed usage, and up to six and a half hours using ASUS' specialty power saving mode (more on that in the software section). ASUS also claims that you can expect up to two weeks of endurance in standby mode -- a claim we naturally did not have time to test.


This is one area where we'd especially prefer to test the kinds of production-level models consumers can expect to find on shelves. For now, though, the laptops issued to tech journalists writing early previews were largely scrubbed of third-party software, save for McAfee Internet Security. Otherwise, you'll find a raft of ASUS-branded utilities, including AI Recovery, FaceLogon, Instant Connect, LifeFrame3, Live Update, Power4Gear Hybrid, PWR Option, Secure Delete, Splendid Video Enhancement Technology, Tutor, USB Charger Plus, Virtual Touch and WebStorage Sync Agent.

As we mentioned briefly, these Zenbooks come loaded with some ASUS-approved power management profiles, which co-exist with the stock options offered on every Win 7 machine. The Power4Gear suite includes four modes in total: Entertainment, High Performance, Battery Saving and Quiet Office. We encourage you to play with these as you're getting settled, but you should know that whenever you unplug the machine, it will default to the Power4Gear Battery Saving mode unless you manually switch to the proflle you want. Likewise, when we started up the machine after our battery test completed, the machine had reverted to one of these specialty profiles, as opposed to balanced mode, which we were using before the battery gave out.

Configuration options

Okay, Ultrabooks are never the most configurable laptops out there, but even here, you've got options. Though we tested a tricked-out UX21A with a Core i7 CPU, 256GB drive and 1080p display, you can save some pennies by going with a Core i5 processor and 128GB SSD instead. Meanwhile, the UX31A will be offered with the same processors, solid-state drives and screen resolutions, but you can also get it with a Sandy Bridge Core i3 CPU at the low end. There's also the lower-end UX32A, a 13-inch model with 1366 x 768 resolution and hybrid hard drives. Rounding out the bunch, the UX32VD is the same as the higher-end UX31A except for one crucial spec: instead of integrated graphics, it has an NVIDIA GeForce GT 620M GPU with 1GB of video memory. Now that we'd like to test!


It would seem, even after spending just a few days with the UX21A, that ASUS has mended its Zenbook line in the areas where it was most lacking. This time around, the trackpad is cooperative while the keyboard is backlit and far easier to type on. Not that the last-gen 1600 x 900 display was a bad thing, but we're not one to complain about an upgrade to IPS and 1080p resolution either. We'll be updating this preview with a final verdict and more detailed processor information once we test a final, production-grade unit and once ASUS gives us a price to help put this all in context. All that said, though, it would be an understatement in the meantime to say we like what we see.