The Microsoft Surface RT is a 'Windows 8' tablet with integrated stand and keyboard running on an ARM processor. We tested the £399 inc VAT 32GB Arm version of the Windows device - the Surface RT - over the course of a week.

Surface RT - Specs and performance

Tablets are like referees: you enjoy their performance only when you don't notice it. In other words, a tablet or smartphone should just work, delivering a user experience that never, ever reminds you a processor is locked inside, chewing up its gears to keep pace with what's happening on screen. Older Windows tablets have resembled low-specification laptops, often with performance to match. But the Surface RT is different, sporting as it does an ARM chip. Is this, then, an iPad running Windows 8?

The Surface RT's 1.4GHz quad-core Tegra 3 processor and 2GB of system memory handle their workloads without drama. Gesturing through the OS itself is fast and fluid. Ditto browsing in Internet Explorer. Websites load extremely quickly, and when you scroll rapidly down pages, screen redraws have no trouble keeping up.

During benchmarking, Surface RT more than held its own against other tablets in the 10-inch hardware class. With a frame rate of 6.9 frames per second, it took first place in our run of the WebVizBench HTML5 benchmark, besting the Asus VivoTab RT (another Windows RT tablet), which achieved a rate of 4.8 fps. And in posting a time of 10.4 seconds in our own punishing webpage loading test, Microsoft's tablet trounced the VivoTab RT (which required 23.3 seconds to load the same page) and even squeaked past the third generation iPad (which clocked in at 10.8 seconds).

Surface RT meets the demands of modern web browsing, but what about performance in more hard-core applications? It's almost impossible to tell, because the Tegra 3 is an ARM processor, and our full PC benchmarking suite runs only on x86-based silicon. We'll be performing our Geekbench performance and Egypt HD gaming tests when we have a Surface of our own to have and hold. Watch this space.

When working in the preinstalled Office apps, we never encountered any bad hiccups or undue lag, but these programs have already been tuned — or perhaps the more accurate word would be detuned — to work within the limitations of ARM processors.

Regardless, performance in hard-core applications probably won't even matter, because the Windows RT desktop is locked down: You will never be able to install Photoshop, traditional PC games, or any other code we typically define as "PC software".

As for the new Windows 8 apps you purchase in Microsoft's Windows Store, they'll be vetted and qualified to run on Windows RT and ARM (Gizmodo reported that 6 percent of all apps in the greater Windows Store inventory lack Windows RT certification). Will the more processor-intensive apps perform without fits and starts on Surface RT, or will they make you wish your first Windows tablet was running Clover Trail or a Core-class CPU? That's the big question, and it should have a direct bearing on what type of Windows device you buy.