A recently published patent reveals that Microsoft (MSFT 1.94%) might build a "modular" PC consisting of a processor, graphics card, hard drive, battery, speakers, wireless card, and other components encased in removable magnetic shells. The shells, which would be similar to Lego blocks, could be easily swapped out from the base, making customizing or upgrading the system much easier. The display, which rests on top of the stack, could also be swapped out.

Source: U.S. Patent Office.

The patent filing also briefly mentions gesture recognition and holographic projection, hinting at compatibility with the HoloLens. Tim Escolin, an industrial designer on the Surface team, co-authored the patent, indicating that it might be developed as a Surface device. The filing doesn't mean that Microsoft will actually launch a modular PC, but we should discuss why the tech giant would even consider creating such a device.

The business of modular computing
Upgrading a traditional desktop today requires opening the case, unscrewing and removing components, swapping in the new ones, and installing drivers. Putting the components into block-like shells saves a lot of time, and Microsoft-branded or approved modular components could be automatically installed and be less likely to cause hardware conflicts.

However, many companies have teased similar products before. In 2014, Razer introduced a similar modular PC concept called Project Christine, but it was never mass produced. Total Geekdom unveiled a similar Micro Lego Computer last July, but it hasn't launched yet either. Acer started selling the core unit of its Revo Build stackable PC, but it hasn't launched any of its modular components yet.

Acer's Revo Build (L) and Total Geekdom's Lego Computer (R).

On the mobile front, Alphabet's Google started testing Project Ara, a modular smartphone, in 2014. The base device only has a frame, touchscreen, and a Wi-Fi module, and users buy and attach additional blocks for the battery, speakers, RAM, and processor. But as I mentioned in a previous article, the Ara is impractical because cheap smartphone reference designs already clump many of those components together -- making them more cost effective than pick-and-choose modular devices.

Google's Project Ara. Source: Google.

What's Microsoft's angle?
After Microsoft launched the Surface, many PC OEMs created similar 2-in-1 devices, sparking a form factor revolution for devices running Windows' desktop and tablet modes. Microsoft might be trying to spark a similar revolution in the desktop market, which has remained the weakest section of the sluggish PC market.

Enterprise customers, which are a key market for the Surface, also still rely heavily on desktop PCs. These customers might think that a modular all-in-one PC with removable shells could be more efficiently upgraded than traditional desktops. These PCs could also complement the Surface Dock, which turns Surface tablets into full desktops, in enterprise environments. Lastly, introducing an all-in-one modular PC would expand Microsoft's Surface line, which already consists of 2-in-1 devices and a laptop.

Why a modular PC will likely fail
The idea of a Lego-like Surface PC is interesting, but I doubt that it will see the light of day for several reasons. First, Microsoft doesn't manufacture first-party CPUs, GPUs, or other components. This means that those third-party manufacturers must agree to create proprietary blocks for Microsoft's PC. Since those components will require extra parts, like magnets and cases, they will likely cost more than their non-modular counterparts for traditional PCs.

There's also no industry standard for modular components, which means that companies would have to create specialized blocks for each modular manufacturer. Moreover, modular PCs will never be as cost-effective as ready-made desktops, because OEMs buy the parts in big bulk orders. Lastly, desktops are dying because tablets, laptops, and 2-in-1 devices can pack comparable horsepower on smaller boards. SoCs and tightly knit reference designs now do the work of multiple hardware devices, so the practice of upgrading individual components is becoming outdated.

Not a mobile-first strategy
Introducing a modular PC at this point would also be a baffling move which contradicts Microsoft's attempt to become a "mobile-first" company. Continuum, for example, can already turn Windows 10 phones and tablets into full-fledged desktops with a $99 Display Dock. Those mobile-centric devices are more elegant "all-in-one" solutions for mainstream and enterprise users than a stack of magnetic shells.

Microsoft already dabbled in modular designs last year with the modular Xbox One Elite controller, which let users swap out the analog sticks, D-pad, or add paddles to the rear. However, a modular PC is a much bigger project than a controller, and one that could dent its growing Surface division if it flops. Therefore, I believe that a modular Surface desktop is an interesting idea, but one that Microsoft definitely shouldn't mass produce.