The brushed aluminium shell is impervious to dust, but not smudging. The keyboard panel is also aluminium, but since it has a matte finish, it deters smudges better than the lid. The bottom section of the chassis, however, is made of plastic, which somewhat clashes with the elegant metal used everywhere else.
The keyboard is well installed in the chassis and includes a numeric keypad. The chiclet keys are nice for typing; the resistance is light and the touch slightly granular. However, on a machine of this calibre, you would normally expect backlighting.
The VivoBook S551LB has a spacious touchpad (10.5 x 7.3 cm) that doesn't stick to the finger. It's a tad overly sensitive, but you can adjust the sensitivity in Asus Smart Gesture, where you'll also find the list of shortcuts that are possible on the touchpad: the classic two-finger scroll, zoom and rotate, as well as a three-finger gesture to bring up the desktop and view all open apps, along the lines of Mac OS X's App Exposé.
The touchscreen is nothing revolutionary. As usual, it's precise enough for the Windows 8 start screen menus, but not quite enough for the standard desktop, where you would need better precision to select folders and small text. We still think touchscreens have no real place on a laptop. But if you are looking for a Windows 8 touchscreen experience, better go with a device like the Lenovo IdeaPad Yoga 13, which has hinges that transform the laptop into a full-on touchscreen tablet.
Unlike many an ultrabook, the VivoBook S551LB has an alright amount of connectivity: two USB 3.0 ports, one USB 2.0 port, Ethernet (RJ45), a headphone/microphone combo jack and an SD card reader, plus a DVD drive—a rare inclusion on an ultrabook. The VivoBook S551LB is proof that yes, you can have a thin laptop that also has ample connectivity.
Heat readings with the components under stress (°C)
Images taken using a Fluke Ti25 thermal imaging camera
Surprisingly for a thin laptop with a dedicated graphics card, the VivoBook S551LB withstood our stress tests without overheating. In the images above, there isn't a single red spot; the hottest it got was 39.8°C. The fan noise also stayed relatively low, at a maximum of 37 dB(A).
But the screen tests we ran were just one disappointment after another. While 1366 x 768 pixels are perfectly fine on a 13-inch display, on a 15.6-inch screen it's really pushing it. Plus, the brightness goes up to just 200 cd/m², which is far too low for use outdoors. The average contrast ratio is a paltry 400:1, which does nothing to help the already narrow viewing angles provided by the TN panel.
Grey colour temperature
And the colours don't help much, either. The Delta E is 6.5, which shows that they aren't particularly faithful (three and below would mean perfect fidelity), and the 8,500 K colour temperature makes for cold tones.
The VivoBook S551LB has a Realtek chipset and uses MaxxAudio, which gives you a number of pre-set audio profiles for the speakers. Not all of them are worthwhile, but since the hardware is relatively good, the digital enhancement adds a nice little boost to the sound quality.
The headphone/microphone combo jack provides clean sound with fairly high volume.
Configuration:The model we were sent to review features an Intel Core i7-4500U processor, 4 GB of RAM, an Nvidia GeForce GT 740M graphics card, a 1 TB hard drive and a 24 GB solid-state drive. The observations above refer to all versions of the Asus VivoBook S551LB, whereas the comments below apply only to the model we tested (see inset below).
The Intel Core i7-4500U is a high-end processor that can handle any task at high speeds. However, for some reason it only slightly outperforms the Core i5-4200U (found in the competing Dell Inspiron 15R), whereas logically there should be a greater difference between the two.
In detail: The VivoBook took 532 seconds to encode an HD video it took the Inspiron 481 seconds to decode, the VivoBook took 286 seconds to compress files the Inspiron took 233 seconds to compress, and the VivoBook took 87 seconds to convert audio files the Inspiron took 110 seconds to convert.
Asus made the right choice to accompany the 1 TB HDD with a 24 GB SSD, as it allows the S551LB to start up and shut down in just 12 seconds.
Most ultrabooks have a lowly Intel HD Graphics chipset to take care of gaming, but Asus decided to bait buyers with an Nvidia GeForce GT 740M. This isn't the most powerful video card on the market, for sure, but it's better than most ultrabooks and will run smaller and bigger video games, such as FIFA 13 or BioShock Infinite, in the screen's native resolution just fine. Of course, for especially demanding games like Crysis 3 or Metro: Last Light, you'll have to make serious sacrifices with the quality settings in order to get decent gameplay.
To play HD movies, the GT 740M isn't even called up to bat, as the Intel HD Graphics 4400 takes care of it flawlessly.
MOBILITY / BATTERY LIFE
The VivoBook S551LB's battery life surpasses every other 15.6-inch laptop we've reviewed (during continuous video playback with the Wi-Fi turned off, headphones plugged in and the screen brightness at 100 cd/m²). In these conditions it lasts 6½ hours, which is even longer than the 15" MacBook Pro with Retina Display, which was the current record holder at 6 hours.
The VivoBook is a bit heavier than the MacBook Pro, (2.4 kg, compared to the 2 kg, respectively). All the same, it's thin enough to fit in an any ordinary backpack.