Microsoft and ARM: A Rocky Romance A Decade in the Making

“Microsoft announces new Surface devices! Their light form factor blends the experience of a traditional laptop with a tablet. A new Windows version, specially built for low-power ARM processors, promises security and performance improvements. It gives users access to their favorite Windows apps with an all-day battery life. Microsoft believes these 2-in-1 gadgets can finally become their Apple-killer competitors.”

You’d think that was referring to the new Surface devices announced at Microsoft’s Copilot+ PC event earlier this month. Or perhaps you thought that was referring to the Surface Pro X, launched in 2019. But in fact, it was actually talking about the Surface RT, launched in 2012.

That’s right; the Copilot+ PC launch is Microsoft’s third attempt to usher in a new generation of Windows devices using the ARM architecture. What happened in the previous two?

2012: Surface is born

The Surface RT was introduced alongside Windows RT, a variant of Windows 8 compiled for ARM processors. Microsoft’s goal with this new device was bold: to create an iPad killer.

In a recent interview with Pavan Davuluri, leader for Windows and Devices at Microsoft, The Verge’s David Pierce asked what the big bet behind the Surface RT was.

“Our core thesis at that point in time, with an ARM bet, was around modernizing the platform and bringing a modern architecture to Windows. […] What we wanted was great performance, great battery life, and security, with a new user experience paradigm.” – Pavan Davuluri, 2024

The Surface RT and its ARM bet ended up becoming a fiasco for Microsoft, but learnings from it paved the way for a billion-dollar business with Surface Pro devices.

There were multiple reasons for this failure, but one of the main ones was the lack of x86 app compatibility. Windows RT could only run specific Microsoft apps ported to the native ARM architecture, like Office and Windows Store apps.

Not being able to run classic x86 Windows apps in 2012 was a death sentence. Both consumers and enterprises had a huge dependency on legacy desktop apps; Microsoft needed developers to jump on the Windows Store wagon, but they ultimately didn’t.

Touted as non-intuitive, the Surface RT’s touch-first interface, coupled with painful software glitches, made it difficult to compete with Apple’s smooth experience on iPads. The Surface RT’s starting price of $499 was also seen as not competitive compared to lower-cost Android tablets and even the entry-level iPad.

On top of that, the RT naming was confusing for consumers, and PC manufacturers didn’t like it either: Dell urged Microsoft to drop the branding, and Samsung decided not to build Windows RT tablets.

Microsoft was left as the only supporter of Windows RT and eventually decided to abandon the product in favor of the Surface Pro line, which shipped with Intel processors and a full version of Windows.

2019: The app compatibility conundrum

Seven years later, the Surface Pro X launched as a new attempt to compete with Apple using an ARM-based processor. Microsoft believed the Surface Pro X provided a perfect mix of mobility, productivity, and speed.

ARM processors typically consume less power than x86 processors for a similar performance envelope, have a simpler design with lower heat generation profiles, and have a more cost-effective manufacturing process. Microsoft started to believe that ARM was finally ready to rival the legacy x86 architecture on laptops. Fanless devices, multi-day battery life, and uncompromised performance: Microsoft wanted a slice of that pie.

Panos Panay, Microsoft’s Chief Product Officer at the time, praised the device’s new SQ1 processor, a custom ARM-based chipset engineered by Microsoft and Qualcomm.

“Better battery life, faster, thinner, lighter, unprecedented performance. All while running the full power of Windows. […] Surface Pro X is also the first Windows PC ever to have an integrated AI engine.” – Panos Panay, 2019

The tech landscape had changed since 2012, and PC vendors like Asus, HP and Lenovo had finally warmed up to the idea of releasing ARM-based devices with Windows. Microsoft released developer tools that allowed building new native ARM apps for Windows 10.

To facilitate the transition to ARM processors and to avoid making the same mistakes Windows RT did years prior, Windows 10 included an x86 app emulation layer. However, this emulation layer had limitations and didn’t work flawlessly: x86 apps would run in a 32-bit emulator, and ARM processors are 64-bit, causing issues like hangs or crashes from time to time. The Surface Pro X’s emulation capabilities with x64 apps were even more limited since Microsoft didn’t officially support them.

Microsoft was aware of these problems and promoted the Surface Pro X as a premium device designed for mobile users who spent most of their time using a web browser or basic apps. This alienated a big portion of Windows users who needed to rely on their apps working without performance issues.

While the Surface Pro X wasn’t a complete commercial failure, it experienced significant challenges that reduced its appeal. Apart from the app compatibility limitations, the Windows on ARM native ecosystem was still nascent, and a high price point put the Surface Pro X at a competitive disadvantage compared to traditional x86-based devices.

2024: A new AI era

The Surface Pro 9 was released in 2022, merging the Surface Pro X brand into the regular Pro line and giving customers a choice: they could choose between the new SQ3 ARM-based processor and Intel’s Core i5/i7 processors.

This naming update further confused customers, who didn’t understand the big disparities in functionality between devices on each architecture. Nonetheless, Microsoft reduced its attention to the ARM-related challenges that Windows laptops had historically experienced while continuing to fix software compatibility problems.

And that takes us to the Surface event in late May 2024, when Microsoft went all-in on ARM with its new Surface devices. For the first time since 2012, a Surface lineup announcement included only ARM-based devices: the new Surface Pro and Surface Laptop.

These new devices are called Copilot+ PCs, and feature the new ARM-based Snapdragon X Elite and Plus processors from Qualcomm. What’s extra special about them is that they come with a first-of-its-kind chip: a neural processing unit (NPU) designed to power new Windows 11 AI features, like Recall.

Regardless, Microsoft is aware that the vast majority of legacy enterprise software still depends on the x86 architecture, and future Copilot+ PCs will also feature Intel and AMD chips.

This hardware launch was also brought up during a recent interview with the leader for Windows and Devices at Microsoft, Pavan Davuluri. In the interview, Davuluri addressed whether Microsoft believes that they have finally solved the app compatibility problem:

“Typically, as a team, we collectively look for a set of signals. In this instance, there were some things that we clearly learned by way of customer feedback. […] There are some front-and-center things that we just had to make sure we were delivering on; emulator performance was one such example.

The other big component is that we do get a chance to talk to customers, we do that for consumers for sure, we talk to commercial customers, we get a chance to do iterations, trials and deployments with them. And so we learn through actual dialogue, data and telemetry to see if we have addressed the core issues.

A great example of that is on the emulator itself. As much as we did tremendous work on the emulator on this iteration, there are some things that you can’t emulate: kernel components in Windows, anti-malware type stuff, and VPN applications that commercial customers do rely on, you have to get them native.”

This realization that emulation can only go so far is interesting because it signals a callout to the developer community. For the Windows transition to ARM to fully work, Microsoft needs active participation from developers. Building native versions of critical apps will become a necessity at some point in the not-so-distant future.

Microsoft is trying to convince developers by giving them access to the Windows Copilot Runtime Library, which will allow the use of over 40 AI models running on Windows 11 for their apps. Developers will be able to integrate image filters –like background blur and eye contact during video calls–Live Captions with AI-powered translation capabilities, and even custom versions of Recall within an app.

Similarly, Microsoft is attempting to persuade consumers by highlighting these new devices as MacBook killers. Yusuf Mehdi, Microsoft’s Consumer Chief Marketing Officer, said the new laptops will be “58 percent faster” than a MacBook Air with an M3 processor and have battery life that lasts “all day.”

Until now, developers were the missing piece, but the new Copilot+ strategy is brilliant. By building unique AI experiences that will become essential for Windows users (), Microsoft is indirectly pushing developers to meet customers where they are: on a modern AI-driven Windows on ARM platform.

Microsoft might be finally holding a winning hand here. Place your bets! Things are about to get interesting.

Image credit: Microsoft