Chips and Cheese has an excellent deep dive into Arm’s latest core design, and I have thoughts.
Arm now has a core with enough performance to take on not only laptop, but also desktop use cases. They’ve also shown it’s possible to deliver that performance at a modest 4 GHz clock speed. Arm achieved that by executing well on the fundamentals throughout the core pipeline. X925’s branch predictor is fast and state-of-the-art. Its out-of-order execution engine is truly gargantuan. Penalties are few, and tradeoffs appear well considered. There aren’t a lot of companies out there capable of building a core with this level of performance, so Arm has plenty to be proud of.
That said, getting a high performance core is only one piece of the puzzle. Gaming workloads are very important in the consumer space, and benefit more from a strong memory subsystem than high core throughput. A DSU variant with L3 capacity options greater than 32 MB could help in that area. X86-64’s strong software ecosystem is another challenge to tackle. And finally, Arm still relies on its partners to carry out its vision. I look forward to seeing Arm take on all of these challenges, while also iterating on their core line to keep pace as AMD and Intel improve their cores. Hopefully, extra competition will make better, more affordable CPUs for all of us.
↫ Chester Lam at Chips and Cheese
The problem with Arm processors in the desktop (and laptop) space certainly isn’t one of performance – as this latest design by Arm once again shows. No, the real problem is a complete and utter lack of standardisation, with every chip and every device in the Arm space needing dedicated, specific operating system images people need to create, maintain, and update. This isn’t just a Linux or BSD problem, as even Microsoft has had numerous problems with this, despite Windows on Arm only supporting a very small number of Qualcomm processors.
A law or rule that has held fast since the original 8086: never bet against x86. The number of competing architectures that were all surely going to kill x86 is staggeringly big – PowerPC, Alpha, PA-RISC, Sparc, Itanium, and many more – and even when those chips were either cheaper, faster, or both, they just couldn’t compete with x86’s unique strength: its ecosystem. When I buy an x86 computer, either in parts or from an OEM, either Intel or AMD, I don’t have to worry for one second if Windows, Linux, one of the BSDs, or goddamn FreeDOS, and all of their applications, are going to run on it. They just will. Everything is standardised, for better or worse, from peripheral interconnects to the extremely crucial boot process.
On the Arm side, though? It’s a crapshoot. That’s why whenever anyone recommends a certain cool Arm motherboard or mini PC, the first thing you have to figure out is what its software support situation is like. Does the OEM provide blessed Linux images? If so, do they offer more than an outdated Ubuntu build? Have they made any update promises? Will Windows boot on this thing? Does it work with any GPUs I might already own? There’s so many unknowns and uncertainties you just don’t have to deal with when opting for x86. For its big splashy foray into general purpose laptops with its Snapdragon Elite chips, Qualcomm promised Linux support on par with Windows from day one.
We’re several years down the line, and it’s still a complete mess. And that’s just one chip line, of one generation!
As long as every individual Arm SoC and Arm board are little isolated islands with unknown software and hardware support status, x86 will continue to survive, even if x86 laptops use more power, even if x86 chips end up being slower. Without the incredible ecosystem x86 has, Arm will never achieve its full potential, and eventually, as has happened to every single other x86 competitor, x86 will eventually catch up to and surpass Arm’s strong points, at lower prices.
Never bet against x86.