Windows 10 with Arm: What You Need to Know Before Buying a Surface Pro X

Windows 10 on Arm is not Windows RT. It's also not the Windows 10 you know. Before ordering a Windows device with Arm as the new Surface Pro X, read this.
One of the most anticipated ads of the Microsoft Surface event in New York last week was the Surface Pro X . The latter member of the Surface Pro family is powered by an Arm processor, which should result in significantly longer battery life and easier 4G connectivity.

Another subject to consider: the very first Surface device, Surface RT, was powered by a Nvidia Arm processor. It is therefore easy to confuse Windows 10 with Arm with its predecessor, Windows RT, which was developed for this device.

It should be clear on this point: Windows 10 with Arm is not Windows RT. This ancestor (at least in technical terms) was limited to Microsoft Store applications, plus a specially compiled version of Microsoft Office. On the other hand, Windows 10 on Arm is a full member of the Windows 10 family, able to run most Windows desktop applications without modification.

The biggest restriction, at least for now, is that these desktop applications work with a 32-bit emulator, even though the Arm processors are 64-bit. This can cause some minor problems, but it's not a real worry.

If you expect an Arm-based Windows notebook to match every detail of an Intel-based PC, you may be disappointed. But if you consider it more like a mobile device that does almost everything a typical laptop can do while doubling battery life, the value proposition becomes clearer.

To understand where the Surface Pro X is in this area, it's helpful to understand how we got there.

A brief history of the computer "always connected"

Microsoft announced its intention to put Windows 10 on architecture Arm in 2016, and the first of these so-called "always connected" PCs (like a smartphone) was announced a year later, at the Qualcomm Snapdragon Tech Summit in late 2017 .

At that time, Windows RT was a distant memory. Microsoft had instead devoted a massive amount of development resources to running Windows 10 on Arm processors. Much of this work was done in the service of Windows 10 Mobile, but because this outdated product shared the same kernel as Windows 10 on PC, it is still relevant.

Support for Windows 10 on Arm came with version 1709 of Windows 10, whose devices running this release were made available in mid-2018.

These first generation machines offered an unimpressive experience. But hardware upgrades for the second generation, announced at the end of 2018, have resulted in a noticeable improvement in performance.

In the last six months, I've been using one of those Arm-based second-generation Windows devices, the Lenovo C630, which is powered by a Qualcomm Snapdragon 850 processor. It's not perfect, and I do not would not recommend unless you understand its limitations. But overall, it's an interesting travel companion, and it helped me understand exactly how Windows on Arm works.