Review:Asus Eee Pad Transformer Prime

Android tablets have come a long way since the early days of bodged smartphone OSes and horrid resistive screens, but there hasn’t been much development since the first Honeycomb tablets hit the shelves in spring this year. That’s about to change, however, with the new Asus Eee Pad Transformer Prime.

This is the follow up to the original Transformer and improves on its design hugely. Gone is the slightly cheap plasticky finish of the original, to be replaced by a much slimmer, sexier body. The new Transformer bears the same “spun” aluminium finish as the firm’s sleek Zenbooks, and it looks and feels lovely.

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It’s as thin as the market leaders, and very light with it too: the tablet on its own weighs 594g. Physically, the new Transformer cedes no ground to its competitors; which you choose will come down to personal taste.

Of course, half the point of buying the Transformer in the first place is its ingenious keyboard dock, a feature you’ll find nowhere else. It, too, has had a redesign, to match the design of the tablet, with keys that have less travel and a firmer base.

The dock mechanism feels as solid and long lasting as it did originally, engaging with a positive click, with a smooth and cultured hinge action.


Combine that with its booster battery, and a USB port that lets you connect a keyboard or USB thumb drive (we tested both NTFS- and FAT32-formatted sticks and both allowed us to read and write files), and you have a very strong-looking package.

A Tegra revolution

Handsome though the Prime undoubtedly is, the main attraction is what’s under the hood. This tablet is the first to feature the new generation of tablet processors: Nvidia’s Tegra 3, which brings a number of significant advancements over the dual-core Tegra 2.

The headline figure is clearly the new chip’s quad-core 1.3GHz processing power, but that doesn’t reveal the full story, because technically Tegra 3 has five cores, and it’s the fifth core that really makes the difference.

Nvidia calls this the “companion” core. It’s low power – running at only 500MHz – and the Transformer uses this core the majority of the time. While in standby, syncing emails and other messages, running low-intensity background tasks, reading web pages, it’s the companion core doing all the work. It can even deal with local video playback once the initial load has taken place.

The only time those four 1.3GHz cores fire up is during high-intensity tasks such as gaming and HD video streaming, launching apps and loading web pages. The rest of the time, they’re simply idle, allowing the companion core to get on with the majority of the work. See the video below for Nvidia’s explanation.

Additionally, Asus puts some control over clock speed under user control: “Balanced” and “Battery saver” modes allow you to manually turn down the wick on the processor, while a “Super IPS+” switch encourages you to use the brightest screen setting only when you’re outside in bright sunlight.

The idea of all this is to provide power at the same time as long battery life, so it was with interest that we embarked upon our stock battery test. This involves (with the screen brightness set to medium) looping a low-resolution podcast video until the battery runs flat, timing how long it takes to achieve this.

The first test, on the tablet portion only, and with the software setting pushed to its highest (Normal) setting, saw the tablet last a slightly disappointing 6hrs 50mins – somewhat down on the manufacturer’s claimed 12 hours, and a long way short of the iPad 2.

To get a feel for the maximum potential battery life, we also ran the test in Battery saver mode, which gave us a far more respectable 10hrs 8mins. And finally we added the base, which extended the battery life of the Transformer to a total of 18hrs 5mins in Battery saver mode – longer life than the original Transformer, which lasted 15hrs 43mins connected to its base.

All in all it’s remarkable performance, especially considering the extra power on tap.


Speed demon?

The performance part of the equation, however, is more difficult to gauge. In theory the Transformer Prime’s Tegra 3 has all-comers beaten, but in benchmarks the advantage wasn’t clear cut.

It started by blitzing the SunSpider test with a time of 1,762ms. That’s faster than any other device we’ve yet come across, but it doesn’t win by a huge margin. The dual-core Motorola Xoom 2 was very close at 1,931ms, the iPad 2 and the Samsung Galaxy Tab 10.1 a little behind this.

On the other hand, our 28-page HTML stress test loaded in an average of 17.6 seconds, noticeably slower than the dual-core Xoom 2’s time of 14.3 seconds and the iPad 2 with 7.7 seconds.

In real-world usage, the benefits are equally unclear. At flicking between Android desktops and menus, this is the smoothest and most responsive tablet to date.

Panning around web pages and scrolling up and down, on the other hand, reveals a slight hesitancy. The lack of responsiveness is noticeable when you compare the Transformer Prime directly with an iPad 2 side by side.

One area where the extra grunt of Tegra 3 does show through is video playback. On the YouTube desktop site, for instance, the 1080p version of the Big Buck Bunny clip played smoothly, where it stuttered on dual-core tablets. With the help of the Diceplayer video app, the Transformer Prime played high bitrate 1080p MKV files without dropping a frame.

However, we suspect the full benefit of Tegra 3 will only become apparent when games optimised for the new chip begin to appear in larger numbers. First-person-shooter ShadowGun is one of the early examples, showing slightly improved textures on the Prime over the Motorola Xoom, although even here gameplay was smooth on both.

The screen and camera

The final piece of the jigsaw is the 1,280 x 800 display, which is simply stunning. Asus uses IPS technology in the Prime, and in all respects it’s a brilliant screen. Maximum brightness is superb at 584cd/m2 – the highest we’ve measured on any tablet, and viewing angles are fantastic.


Although the glossy screen does pick up fingerprints at an alarming rate, the extra brightness means it’s pretty readable, even in bright outdoor conditions. Colours also leap out with superb vibrancy – at least on a par with the iPad 2 and the Samsung Galaxy Tab 10.1.

The 8-megapixel camera on the rear of the Prime, meanwhile, has the beating of every other tablet on the market both in terms of stills and its 1080p video. In good light pictures are crisp, colourful, and boast good detail, although for quality it still can’t match the best smartphones.


If we’re honest, Tegra 3 came as a little bit of a disappointment. We had been hoping for iPad-beating levels of responsiveness, smoothness and battery life. The Prime doesn’t quite offer that, and although the new chip does boost HD video and the potential for high-end gaming, the companion core setup seems to compromise some aspects of browsing performance.

However, the rest of the package is much more likeable. It’s an improvement over the original in most respects (and most other Android tablets), with better battery life, a superb screen, a good camera and much slicker design.

It’s pretty good value too. The 32GB Wi-Fi keyboard and tablet bundle is £499; the 32GB Galaxy Tab 10.1 is the same price. Disappointingly, though, you can’t buy the tablet on its own, which dampens its appeal somewhat.

So the Prime isn’t perfect, but it does edge in front of the Galaxy Tab 10.1 on value, connectivity and all-round performance. It’s our new favourite Android tablet – and a hint of things to come.