Battery Eater: 181 minutes
3D Mark 06: 4,746
The Intel Core i7-3517U processor that drives the Dell XPS 12 is one of the best you'll find, and unsurprisingly it flew through our tests.
The score of 10,557 in Cinebench is comparable to full-form factor machines such as the Asus Zenbook Prime, showing that compromising on size, gaining portability and even having the option to use your laptop as a tablet doesn't mean you have to sacrifice on pure power.
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A score like this shows that the Dell XPS 12 is worthy of any computing task, as you'd expect from any laptop branded with Dell's high performance moniker.
The beefy chip doesn't mean it's heavy on battery either. Our tests involve subjecting laptops to highly stressful conditions, including looping a simple writing test while simultaneously looping 1080p video.
With all of this in mind, the Dell XPS 12 still managed to run for 181 minutes, which means you'd be able to watch a full movie before reaching for the power cable.
To put this in perspective, the MacBook Pro 13-inch with Retina display managed a score of just over four hours, in more demanding conditions, so while the Dell isn't far shy of the top performers, it's still a score that can easily be improved upon.
However, if you are looking for a Windows tablet and are considering an RT version, you'll see the biggest difference in comparative longevity. Microsoft Surface RT lasted for over seven hours of continuous 1080p video playback, which makes it a definite consideration in our eyes.
Since there's no dedicated video chip included, the graphics score was disappointing. Most day-to-day tasks will be catered for easily, but high-end gaming is out.
If you do need to edit HD video or edit huge batches of pictures, however, look no further, because there's so much power in the processor, this shouldn't be a problem.
Touchscreen performance was also excellent, and the Dell sports 10-finger recognition, which means even the most frenzied touch-typist will get on well with the on-screen keyboard.
If there's one complaint, it's that the 1080p resolution makes everything appear smaller, and this has a negative impact on usability in the traditional Windows desktop. Luckily you'll always have the mouse trackpad to hand.