Asus Eee Pad Transformer Prime Review

The Asus Eee Pad Transformer was one of our favourite products of last year. Asus added a keyboard to an Android tablet, designing an excellent mechanism for fixing the two together and produced a device that worked well in both tablet and clamshell-notebook modes.

We were slightly less impressed with the Eee Pad Slider, but appreciated the variation on the Android tablet/keyboard combo design.

Now Asus has taken the two-part Transformer to the next level, adding a quad-core processor — the first to appear in any Android-based device —and Android 4.0 (Ice Cream Sandwich) into the mix. The result is the very impressive Transformer Prime.

Design
As a tablet, the Eee Pad Transformer Prime is inevitably going to be compared to Apple's iPad and the Samsung Galaxy Tab 10.1, as well as to its predecessor. It comes off well in all cases.

The Transformer Prime is a 10.1in. Android tablet with a quad-core CPU and a keyboard unit that turns it into a clamshell notebook

Weighing 586g, the Transformer Prime shaves almost 100g off the 680g Transformer, comes very close to the 565g Samsung Galaxy Tab 10.1 and is lighter than the 613g iPad 2 (Wi-Fi+3G version).

The Prime's measurments — 26.3cm by 18.08cm by 0.83cm — are significantly more svelte than the original Transformer's 27.1cm by 17.1cm by 1.3cm. It's also slimmer than both the Galaxy Tab 10.1 (0.86cm) and the iPad 2 (0.88cm). You should find it comfortable enough to hold the Transformer Prime in one hand for extended periods.

The metal backplate has a slightly purple sheen, which continues on both sides of the keyboard section. The edges curve slightly towards the backplate, adding to its sleek appearance. It does make finding the edge connectors and buttons a little awkward, though — you have to twist the tablet to find slots.

The slots and connectors are in slightly different positions compared to the original Eee Pad Transformer. Holding the Transformer Prime in landscape mode (with the 1.2-megapixel camera above the screen), there's an audio jack on the right edge. The power button sits on the left side of the top edge, while the left edge houses a volume rocker, a micro-HDMI port and a microSD card slot. There's a 40-pin connector on the bottom edge that's used for PC sync, connecting to the keyboard section and charging the battery.

It's a real pity that there's no USB charge slot on the tablet — or on the keyboard section. This is the same situation as with the original Transformer, and it means you have to carry a dedicated AC adapter when travelling. These days that's not really acceptable.

The LED-backlit Super IPS+ screen measures 10.1in. across the diagonal and has a resolution of 1,280 by 800 pixels. It uses tough scratch-resistant Gorilla Glass, but — like all tablet screens — attracts fingerprints and will need a regular wipe. The image quality is clear, sharp and vibrant, with excellent viewing angles. Watching video and reading web pages on the Transformer Prime is a particularly pleasant experience. It's also easily viewable outside, which is not always the case with tablets.

As well as the 1.2-megapixel front camera there's a flash-equipped 8-megapixel camera at the back. It'll shoot 1080p HD video too — most good tablets (and smartphones) can only manage 720p. Our test images were of a quality we'd happily share with other people.

The keyboard unit is as thin and light as the tablet measuring 26.3cm by 18.08cm by 0.8–1.04cm and weighing 537g. It's made of the same metal as the tablet's backplate, and has the same purple sheen.

The keyboard itself is an isolation-style design, with a full set of QWERTY keys and a number row. The keyboard is comfortable to use, although we'd prefer a little more return from the keys. Above the number row further keys provide Android-specific shortcuts for screen brightness, Bluetooth and Wi-Fi, taking a screen grab, volume control and media playback.

There are Home, Menu and cursor keys, and a multitouch trackpad that controls a cursor on all screens as well as handling functions like text selection and tap-to-zoom. Generally you don't need to tap the screen with the Transformer Prime in notebook mode.

That's a good thing, because —like its predecessor — the Prime is not weighted like a standard notebook, and suffers from a propensity to topple backwards when you tap the screen.

Tiny arrows on the keyboard and tablet help you line up the docking port, and as you push the two halves together the locking mechanism slips in place firmly. When joined, the two sections look as though they belong together, and the general look-and-feel is that of a small ultrabook.

The keyboard has a USB 2.0 port and SD card reader on its right edge. The USB stick we tried worked flawlessly. A 40-pin charging/PC connection port sits on the left edge. The keyboard contains a second battery, which we'll come to later.

Features
The standout technical features of the Asus Eee Pad Transformer Prime have to be that it has a 1.3GHz quad-core Nvidia Tegra 3 processor and runs on Android 4.0 (Ice Cream Sandwich). Anyone buying the device running Android 3.2 (Honeycomb) will be able to get an upgrade. Our review sample was running Android 4.0 and had 1GB of RAM.

The Transformer Prime runs version 4.0 of Android (Ice Cream Sandwich)

The processor has a trick up its sleeve designed to help conserve battery power: it has a fifth core that runs at a much slower speed — just 500MHz — and handles 'tick-over'-style activities with minimal power draw. You can also choose between power-save, balanced and performance CPU modes.

Wi-Fi (802.11b/g/n), Bluetooth (2.1+EDR) and GPS are present, but there's a notable absence of mobile broadband support. For some potential buyers, this may prove to be a glaring omission.

Our review model had 32GB of internal storage, 25GB was available out of the box. You can add more capacity via microSD, SD and USB using the various ports. You also get access to 8GB of online storage via Asus WebStorage.

Asus has provided a number of extra apps suitable for a tablet with a well-integrated keyboard.

Polaris Office lets you create and edit Microsoft Office-compatible files

Polaris Office is a useful tool for creating files that are compatible with Word, Excel and PowerPoint. An additional note-taking application, SuperNote, offers two data-entry options: typing and freehand writing; or drawing with paint tools. You can insert drawn pages into text-based pages.

Other applications include MyLibrary for reading e-texts, and MyNet for sharing music, photos and video via DLNA. There's also the TegraZone app, which aggregates a range of games that make the most of Nvidia's Tegra processors. Finally, you get the full Android Market and a competent file manager.

Performance & battery life
The Eee Pad Transformer Prime's 1.3GHz Nvidia Tegra 3 processor offers absolutely stunning response times — most of the time. Screen taps produced an almost instantaneous response; screen rotation was swift too. But not everything was lightning fast: Google Maps took a while to resolve full screen, and flicking between web pages was slower than we'd anticipated. Still, there was nothing in the performance here that we couldn't live with.

Audio quality is surprisingly good. Although there's only a single speaker on the back of the tablet, audio output is fairly loud and reasonably punchy. Plug in a good pair of headphones and the sound quality is perfectly acceptable for everyday use.

According to Asus, the tablet's 25Wh Li-polymer battery is good for 12 hours of life. The keyboard adds a second 22Wh battery, which Asus claims can boost this to 18 hours. That's two hours more than the original the Eee Pad Transformer.

We tested these claims by looping music continuously with and without the keyboard attached. In both cases we set the processor to Balanced mode (as opposed to power save and performance modes) and the screen brightness at 50 percent. We had Wi-Fi on throughout the test.

In tablet only mode we got 7 hours 58 minutes of music playback. When the battery was drained we attached the tablet to the keyboard which we'd previously fully charged. This delivered a further 5 hours 36 minutes, for a total of 13h 34m.

Interestingly, while the keyboard battery was being used, it was also charging the tablet section. When the keyboard had drained itself to zero the tablet had raised itself to 30 percent. In our test, we left the keyboard and tablet attached while this last 30 percent was used and it's recorded in the keyboard-attached time above. This is a great feature, as it meant we could have removed the tablet for a bit of keyboard-free use had we wanted to.

Conclusion
Like its Transformer predecessor, the Eee Pad Transformer Prime impressed us greatly. Quite simply, it's the best marriage of screen and keyboard we've seen in a tablet.

The quad-core Tegra 3 processor is no gimmick: its extra speed and punch gives the Transformer Prime professional-level performance. Battery life is excellent too, and we like the way the keyboard charges a drained tablet unit.

Unfortunately, Google's Android still lacks the business software to be a professional's primary operating system, and the Transformer Prime is an expensive second computer. However, if you're primarily looking for a tablet, and value the Prime's enhanced ability to create and edit documents, it's a compelling prospect.

Editor's note 3/2/2012
A leading retailer, Clove Technology, has withdrawn the Asus Eee Pad Transformer Prime from sale, explaining in a statement that "We are at this time not satisfied that all units we could provide you with are working correctly, and performing to the standard we expect of the unit." See our blog post for more on this issue.