One device that does it all is the dream of any PC power user, digital professional or gamer. The seemingly mythical machine that's powerful enough for games or graphics work, yet light enough to carry with you to another room or on the train, is something many laptop manufacturers have gone after, with mixed success. Now, it's Razer's turn.

The maker of gaming hardware moved into the mobile productivity space in 2016 with the Blade Stealth, an ultrabook that borrowed the company's trademark black aluminium and customisable lights, but wasn't powerful enough to do any heavy lifting. Like most devices in its category, the Stealth is focused on portability.

At the time Razer also introduced a product called the Core; a massive, heavy enclosure that could fit your favourite full desktop graphics card and confer its power to the Stealth via USB-C for at-home use. The promise was that your Blade Stealth could travel around with you all day, barely weighing anything in your backpack, but at home you could add powerful graphics capabilities, plus connect to all your accessories, with a single cable.

The original Core never released in Australia, and was given a lukewarm reception overseas owing to its limited compatibility with bigger cards and non-Razer laptops. I've been testing the latest version of the device, the Core V2 (which is available to Australians), and while it's not a sure-fire way to turn your ultrabook into a graphical beast it is very intriguing solution.

Theoretically, as an external graphics card enclosure with an integrated dock for peripherals and monitors, the Core is an ideal machine for those chasing the "one device". It looks great on the desk, with an LED-lit window giving a peek at the undoubtedly expensive card inside, and a vented design that makes it look like a compact PC.

Pulling out the tray and installing a card is easy enough, even if it does feel a bit like defusing a nuclear weapon, and then it's simply a matter of attaching your monitors, keyboard, mouse, ethernet cable and anything else to the ports on the Core's rear. When you connect the machine to your laptop via a USB-C cable, which also charges the laptop's battery, you don't even need to reboot. You get the power of the graphics card immediately.

Though it might be plug and play, this is not gear for novices. The Core is aimed at the user that already has a premium laptop or ultrabook, offering an alternative to building and maintaining an expensive gaming PC as well. And even so, building a competent rig around the Core does not seem easy.

The main limiting factor is still compatibility. First and foremost you'll need to find yourself a PCIe graphics card with a compatible chipset from NVIDIA or AMD. Razer has an official list here. The Core V2 is roomy and fits tall and double wide cards, but older chipsets may not work or may require special software to be able to handle stopping and starting as you plug and unplug.

Next you need a laptop with a Thunderbolt 3 USB-C port and external graphics support. These are becoming more common but are far from ubiquitous. Of course Razer's latest line of Blade laptops all sport them, while some popular laptops — including Microsoft's Surface Book 2 — have USB-C but no Thunderbolt 3, which confuses things.

With all your ducks in a row, the Core functions more or less exactly as advertised. After using my Blade Stealth to do some light work in the loungeroom, I attach it to the Core — containing a GeForce GTX 1080 — in my office and it becomes the heart of a full gaming rig with enough performance to smoothly handle Subnautica or Civilization VI at decent settings, something the laptop could never do on its own.

One issue I did run into is that the performance of USB peripherals attached to the Core had a tendency to become unreliable, and I ended up plugging my keyboard and mouse directly into the laptop whenever I used it. This is obviously not ideal, but perhaps inevitable with so much information going through a single cable. It's hard to say whether this could be improved on the NVIDIA software end, but in any event plugging in two cables to the laptop instead of one is a minor annoyance.

More concerning is that, at $720, it's not clear to what degree the Core offers a cost-effective alternative to simply building a separate desktop machine. You’ll need a really nice (and expensive) laptop to make a great setup incorporating the Core, I'd suggest a Core i7 and at least 16GB RAM if you're going to be gaming, and of course there's little chance of upgrading those specs piece by piece like you can with a full tower. A compatible graphics card is also going to set you back at least a grand, unless you have one floating around already.

Aside from letting you re-use the guts of your laptop for home use, the Core does save you having to buy a case, motherboard, power supply and fans for a separate PC, and of course it has that all-important one-machine-to-do-it-all appeal. But all things considered it does seem like a lot of money to spend, and a lot of pressure to put on your ultrabook's RAM and CPU, to chase that particular dream.