Enlarge (credit: Microsoft)

The Windows 11 24H2 update isn’t scheduled to be released until sometime this fall, but testers can get a near-final version of it early. Microsoft has released Windows 11 24H2 build 26100.712 to its Release Preview testing channel for Windows Insiders, a sign that the update is nearly complete and that the company has shifted into bug-fixing mode ahead of general availability.

Microsoft has generally stuck to smaller but more frequent feature updates during the Windows 11 era, but the annual fall updates still tend to be a bigger deal. They’re the ones that determine whether you’re still eligible for security updates, and they often (but not always) come with more significant under-the-hood changes than the normal feature drops.

Case in point: Windows 11 24H2 includes an updated compiler, kernel, and scheduler, all lower-level system changes made at least in part to better support Arm-based PCs. Existing Windows-on-Arm systems should also see a 10 or 20 percent performance boost when using x86 applications, thanks to improvements in the translation layer (which Microsoft is now calling Prism).

Enlarge (credit: Microsoft)

Here at Ars, we’ve been around long enough to chronicle every single time that Microsoft has tried to get Windows running on Arm-based processors, instead of the Intel and AMD-made x86 chips that have been synonymous with Windows for more than three decades. The most significant attempts happened in 2012 with Windows RT, which looked like Windows 8 but couldn’t run any x86 Windows apps; and in 2017 when Windows 10 Arm PCs arrived with rudimentary x86 emulation.

The main PC company backing each of those Arm efforts was Microsoft itself, which launched the original Surface to showcase Windows RT and the first Surface Pro X during the Windows 10 era. Since then, Microsoft has periodically refreshed the Arm version of the Surface tablet while continuing to sell Intel versions. A couple of PC OEMs put out Windows RT tablets, and most of them took a stab at one or two Windows 10-into-11-era Arm PCs. But there was never a big unified push that made it clear that the entire consumer PC ecosystem had bought into Arm.

This week’s announcements felt different—yes, there was a new Surface Pro and Surface Laptop from Microsoft leading the charge (and the new Surface Pro is the first Surface Pro ever to ship Arm as the default option for most people). But the Surface launch was accompanied by a major wave of systems from essentially every major PC OEM, suggesting at least some level of elevated enthusiasm for the Snapdragon X series that didn’t exist for older Arm chips.

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  Microsoft's Surface Pro 11 comes with Arm chips and an optional OLED display panel. [credit: Microsoft ]

If at first you don't succeed, try, try again.

Microsoft has announced a pair of new devices powered by Qualcomm's Snapdragon X Plus and X Elite processors. They're far from Microsoft's first PCs with Arm processors in them—2012's original Surface, the Surface Pro X, and the Surface Pro 9 with 5G have all shipped with Arm's chips instead of Intel's or AMD's. But today's new Surface Pro and Surface Laptop are the first Arm devices to be the primary Surface offerings rather than a side offering, and they're the first to credibly claim that they can both outperform comparable Intel- and AMD-designed chips while offering better battery life, a la Apple's M1 chip in 2020.

One caveat that I hadn't seen mentioned in Microsoft's presentation or in other coverage of the announcement, though: Microsoft says that both of these devices have fans. Apple still uses fans for the MacBook Pro lineup, but the MacBook Air is totally fanless. Bear that in mind when reading Microsoft's claims about performance.

Enlarge / The new Arm-powered Surface Laptop. These Copilot+ PCs are all pictured with a refreshed version of Windows 11's "Bloom" wallpaper. (credit: Microsoft)

Microsoft is announcing some fairly major changes for Windows and the Surface lineup as part of its Build developer conference this week, but there’s one thing that’s definitely not coming, at least not right now: a Windows 12 update.

Speculation about the “Windows 12” update began propagating at some point last year in reports that suggested that Microsoft was shifting back to a three-year release cycle like the ones used for Windows Vista, 7, 8, and 10 in the late 2000s and early 2010s.

And Microsoft may have intended to call this fall’s release “Windows 12” at some point, and it does come with substantial changes both above and under the hood to better support Arm systems and to emphasize Microsoft’s AI focus.

Enlarge (credit: Microsoft)

Microsoft is using its new Surface launch and this week’s Build developer conference as a platform to launch its new “Copilot+" PC initiative, which comes with specific hardware requirements that systems will need to meet to be eligible. Copilot+ PCs will be able to handle some AI-accelerated workloads like chatbots and image generation locally instead of relying on the cloud, but new hardware will generally be required to run these workloads quickly and power efficiently.

At a minimum, systems will need 16GB of RAM and 256GB of storage, to accommodate both the memory requirements and the on-disk storage requirements needed for things like large language models (LLMs; even so-called “small language models” like Microsoft’s Phi-3, still use several billion parameters). Microsoft says that all of the Snapdragon X Plus and Elite-powered PCs being announced today will come with the Copilot+ features pre-installed, and that they'll begin shipping on June 18th.

But the biggest new requirement, and the blocker for virtually every Windows PC in use today, will be for an integrated neural processing unit, or NPU. Microsoft requires an NPU with performance rated at 40 trillion operations per second (TOPS), a high-level performance figure that Microsoft, Qualcomm, Apple, and others use for NPU performance comparisons. Right now, that requirement can only be met by a single chip in the Windows PC ecosystem, one that isn't even quite available yet: Qualcomm's Snapdragon X Elite and X Plus, launching in the new Surface and a number of PCs from the likes of Dell, Lenovo, HP, Asus, Acer, and other major PC OEMs in the next couple of months. All of those chips have NPUs capable of 45 TOPS, just a shade more than Microsoft's minimum requirement.

Enlarge / A PC running Windows 11. (credit: Microsoft)

Microsoft is going all-in on Arm-powered Windows PCs today with the introduction of a Snapdragon X Elite-powered Surface Pro convertible and Surface Laptop, and there are inevitable comparisons to draw with another big company that recently shifted from Intel’s processors to Arm-based designs: Apple.

A huge part of the Apple Silicon transition’s success was Rosetta 2, a translation layer that makes it relatively seamless to run most Intel Mac apps on an Apple Silicon Mac with no extra effort required from the user or the app’s developer. Windows 11 has similar translation capabilities, and with the Windows 11 24H2 update, that app translation technology is getting a name: Prism.

Microsoft says that Prism isn’t just a new name for the same old translation technology. Translated apps should run between 10 and 20 percent faster on the same Arm hardware after installing the Windows 11 24H2 update, offering some trickle-down benefits that users of the handful of Arm-based Windows 11 PCs should notice even if they don’t shell out for new hardware. The company says that Prism's performance should be similar to Rosetta's, though obviously this depends on the speed of the hardware you're running it on.