The ARM PC tipping point

What do Apple, Nvidia, Qualcomm, and AMD have in common?

Here are three tangentially connected things that happened over the past week:

• Reuters reported that Nvidia and AMD are designing ARM-based CPUs for Windows PCs.

• Qualcomm previewed its upcoming chip lineup, including the Snapdragon X Elite SoC, which is designed for Windows laptops.

• Apple announced, then broadcast, a Mac-focused event highlighted by its latest M3 generation of Mac chips.

In other words, it's been a big week for ARM processors in personal computers. Apple has completed its transition away from Intel, of course, and it’s hard to call the switch to Apple Silicon anything other than a huge success. Macs are more powerful than they’ve ever been, not to mention longer-lasting, cooler, and quieter.

Things have not gone quite so well on the Windows side, for both hardware and software reasons. But recent news suggests that there’s going to be real change coming to the Windows-on-ARM space soon.

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Let's start with Qualcomm, the dominant player in smartphone silicon design. Qualcomm makes the fastest chips available for Android phones; its current flagship model in most of the world is the Snapdragon 8 Gen 2, and the Gen 3 just launched last week in the Xiaomi 14 Pro.

Qualcomm licenses the ARM instruction set architecture from what is now stylised as Arm, a British company that dates back to the '80s and the days of Acorn Computers. ARM processors became dominant in mobile devices well before the rise of smartphones because of their power efficiency and low cost. As smartphones turned out to be a transformational technology with ever-increasing needs, ARM processors have been scaled up and deployed in more advanced products.

Arm also designs CPU and GPU cores that licensees can make use of. For example, the 8 Gen 2 has one Cortex-X3 CPU core, two Cortex-A715 cores, two Cortex-A710 cores, and three Cortex-510 cores. All of these are off-the-shelf Arm designs with different capabilities and clocked at different speeds in order to handle various workloads. But the chip has an Adreno 740 GPU, which is technology of Qualcomm's own. The precise blend of Qualcomm design and Arm IP is ultimately what makes up a particular Qualcomm chip.

The new Snapdragon X Elite chip is notable because Qualcomm is handling the CPU design itself. This dates back to the 2021 acquisition of Nuvia, a semiconductor startup founded and led by Gerard Williams, who was previously chief CPU architect at Apple. Qualcomm's new custom "Oryon" CPU core is the first product to come out of the acquisition.

The Snapdragon X Elite is a 4nm chip built around 12 Oryon cores clocked at 3.8GHz — there aren't any lower-performance cores focused on efficiency. That suggests Qualcomm is confident in the Oryon core's ability to scale up and down as necessary. For comparison, the company's highest-end Windows chip until now had four 3GHz Cortex-X1 cores and four low-power 2.4GHz Cortex-A78 cores. The X Elite is a massive leap in power on paper.

"On paper" is, of course, an important caveat considering that there are no actual devices yet that use this chip. There are countless variables in terms of battery capacity, thermal management, and so on that could affect its performance. But running desktop-class operating systems on ARM processors is not a weird or exotic notion.

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You can ask Apple, which just introduced the M3, M3 Pro, and M3 Max chips. All three can be found in new models of the MacBook Pro — which now comes in black — while the 24-inch iMac has been updated with the baseline M3.

Apple is not necessarily claiming huge CPU performance increases with the M3 line; most of the comparisons in its event were to the M1 generation, or even to legacy Intel Macs. The focus is more on GPU performance and power efficiency this time around. You get hardware-accelerated ray tracing support on the GPU, for example, while Apple says the M3 MacBook Pro has the "longest battery life ever in a Mac".

Apple might not be able to squeeze out gigantic speed boosts every year, but no-one doubts that moving the Mac to ARM was the right thing to do. Every single Mac is just a dramatically better computer than it was before 2020. I'm writing this on my M1 Mac mini, which is nearly three years old and still hard to fault.

Why, then, has it taken so long to move Windows in the same direction? And what does it mean for Qualcomm's renewed effort in the space — not to mention Nvidia and AMD's?

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In truth, Microsoft was pushing Windows on ARM long before Apple made the shift with the Mac. Its first Surface computer in 2012 had an Nvidia Tegra 3 processor ran Windows RT, an ARM-based version of Windows 8. It was a failure, but that was on Windows 8 as much as it was on ARM; Windows RT devices could only run apps from the Windows 8 store, an initiative that was doomed from the start.