We've seen devices of this ilk before, not least in the form of the Motorola Atrix 4G released a staggering five years ago, but HP believes it has overcome the barriers that have previously prevented all-in-one smartphone solutions from replacing all of the gadgetry in your pocket and bag.

The HP Elite X3 is a 6-inch phablet that can, through the use of a couple of optional accessories, also become a desktop PC and/or notebook.

And although the idea is very similar to convertible phones that have come before, HP says its device differs in that it is the first to market with the processing power good enough to rival conventional laptops.

Pocket-lintHP Elite X3-1-2

That's because the HP Elite X3 sports the all-new Qualcomm Snapdragon 820 system on chip. It is, we were told during a briefing in London prior to the phone's unveiling at Mobile World Congress, as powerful as any other mobility processor out there, but uses less power.

The phone also has 4GB of LPDDR-4 RAM and a Cat 6 LTE modem for good measure. And a sound system that comprises two front-facing speakers that have been optimised by Bang & Olufsen.

Its battery is massive in charge, not so in size in order to keep the handset to a respectable thickness. It is 4,150mAh, so should last an entire day. And other specifications include Corning Gorilla Glass 4 to protect that 6-inch "high resolution" screen, IP67 water and weatherproofing, active noise cancellation on the microphone for clear videocalls and such, and an 8-megapixel front-facing camera that combines two images taken at the same time to improve the video pictures captured in low light circumstances.

Pocket-lintHP Elite X3-6

The latter couple of features are specifically important as, you might have guessed already, the Elite X3 is not designed for consumer use. Instead, it is aimed at the commercial market and that is why HP believes it will succeed in an All-in-one device where others have previously failed.

Corporate IT departments will embrace the phone, HP feels, because it is easier to keep one device secure than three. Yet this one can still perform the functions of other kit a company might normally hand out to employees.

To that end, the Elite X3 has extremely high levels of security built-in. Not only are there secure boot and image encryption, and Bitlocker and VPN-SSL encryption measures, the phone uses two biometric scanners for user identification - fingerprint and iris.

The phone is also dual SIM enabled as standard, giving the user the option to have two localised SIMs if they travel between countries and therefore cut down on roaming charges, or even use one SIM for business the other for personal calls.

And it is a Windows 10 device, which is important when using it with docking solutions.

Pocket-lintHP Elite X3-15

The desktop dock sounds a bit like the Microsoft own-brand equivalent but has a number of key connections that are important in this day and age. USB-C and USB-A ports are present, as is HDMI out. There is an Ethernet port too for wired internet connectivity.

It's weighty, we found, but small enough to fit into a bag if you really want to travel with one. However, you'd also need a wireless keyboard and mouse to get the most use from it.

Thanks to Continuum - Microsoft's Windows 10 technology that resizes the user experience to best suit a display automatically - you only need to slot the phone into the dock and the homescreen on the monitor will take the appearance of a full desktop PC.

It's quick, we found, and works well with basic productivity apps, such as Word, PowerPoint and the like. We didn't get a chance to see how the system adapts for entertainment apps, but suspect IT departments would frown on such a thing anyway.

Pocket-lintHP Elite X3-1-2

We also didn't really get a chance to see the notebook accessory - the Mobile Extender, as it is called - in action. We felt it but because it was a prototype it wasn't fully working yet.

We do know it can connect wirelessly to the phone though, rather than sport a physical dock. But if you want a completely latency free experience, you are advised to hook it up through USB-C.

In all other senses, it has the size and feel of a 12.5-inch laptop with a slim bezel around the screen, HDMI out and a large extra battery that runs independently to that in the handset.

HP explained to us that there will be other accessories too. There will be jackets that encase the Elite X3, for example, that introduce additional functionality thanks to five exposed pogo pins on the rear of the phone that will talk to the external case.

HP detailed a couple it is working on - one rugged for more extreme working conditions, one that adds a card scanner and other features that would fit a retail environment.

First Impressions

It is with the jacket add-ons that the HP Elite X3 makes the most sense.

It is a multi-faceted phone designed specifically for the worker in mind, yet can morph and transform for multiple uses. And with business grade security it might sway companies into finally ditching their staff's BlackBerrys for something that can also replace their existing HP laptops too.

Ultimately though, pricing for firms will be key. We're yet to find that out - most likely closer to launch in the summer - but whatever it is, it'll probably be cheaper than the three separate alternative solutions combined.