When we first heard word of the Alienware M11x, we raised an eyebrow. The company, famous for its mammoth gaming machines claimed it was planning the world's most powerful ultra-portable laptop, with an 11-inch screen but the ability to play Crysis. Surely this was a mis-timed April Fool's joke? But no - the Alienware M11x is real, and we've given it a thorough going over to find out exactly whether the combination of high power gaming and portability actually works. 

First things first - the exterior of the M11x looks almost identical to its bigger brothers, the M15x and M17x. There's the same sloped vents on the front, the same tiny lit-up alien head on the back, and the same premium glossy finish. It's got all the customisation features of its older brothers, too - including the ability to modify the colours of all the lighting. If you plan to use it in public, you'll likely want to turn off some of that immediately. It comes in two colours - black and grey.

It's weighty, at 1.8kg, but feels very solid to hold - as if there's a massive amount of stuff packed inside. The screen is clear and bright, and runs at a very pleasant 1366 x 768 resolution - more than ample for a machine of this size. We had issues with the vertical viewing angle - contrast disappears very quickly if you're not viewing it at exactly the right angle - and we also found the glossy screen a nightmare when it was sunny, even on full brightness settings.

Inside our review model, there was a dual core Intel U7300 CPU running at 1.3GHz, 4GB of RAM, a 256GB SSD hard disk and - the star of the show - an Nvidia GeForce GT 335M graphics card with 1GB of GDDR memory that can be switched on and off when required. If you're playing a 3D game, it'll give you all the power you need, but if you want to save battery then you can turn it off using a keyboard shortcut. It doesn't feature Nvidia's auto-switching Optimus technology, but that could potentially be an option for the machine in the future.

The combination of a hefty graphics card, fast hard disk, respectable processor, plenty of memory and - crucially - low screen resolution means that games run remarkably well. Alienware cautioned us, before we received it, that it's "not in the same league" as the company's larger machines, so the first thing we did when it arrived was install Left 4 Dead 2, push all the settings to max and fire up a game, expecting to laugh at it as it struggled.

It didn't struggle. It delivered a perfectly playable experience. Sure, framerates weren't quite as high as they might be, but notching the settings down just a tiny bit allowed it to run silky-smooth. With Valve's reputation for excellent optimization of its games in mind, we reached for other titles - BioShock 2, Modern Warfare 2 and World of Warcraft with a massive pile of memory-sucking user add-ons. The M11x ate them all up and spat them out with no trouble - not always on top top settings, but never far from them.

We were impressed, too, by the cooling. Although our review machine hasn't had time to accrue a thick coating of dust, the fan that kicks in when you start up a demanding game will shut off again less than 10 seconds after you finish a game, and the base of the machine never got uncomfortably hot during play.

Unfortunately, as a result of the machine's small size, the keyboard feels cramped and uncomfortable. While using the WASD keys in a game is fine, doing any serious writing work will give you wrist pains after a short while. Still, this isn't the kind of machine you'd buy to write the great American novel on, is it? Similarly, you're not going to be able to do much gaming with the trackpad, but we were impressed with its tactility during general use.

The battery is an 8-cell number which Alienware has been forced to integrate into the chassis - meaning that it's not user-replaceable. That won't be an issue when you buy the device, but after a year or two of use - especially if you leave it plugged in a lot - you might find that you're stuck with a dead machine that has to be shipped off to Dell for a replacement. It also means that you can't pack a spare for it if you know you'll be out of range of a charger for some time.