ARMv9: What is the Big Deal?

What is a Scalable Vector Extension? What does it mean to the industry and users? What is behind the jargon?

Erik Engheim
Level Up Coding
Published in
22 min readApr 3, 2021

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If you are a cellphone user, then you know ARM chips: they power your phone, and now they are powering the next generation Macs. They are also making major inroads into the server space.

We are at a cusp of a major shift in industry, the likes of which has not been seen in decades. Yes, this sounds dramatic, but x86 has been dominating the computing industry for decades, and is likely facing its biggest challenge ever with the rise of ARM.

This battle won’t be settled this year, but now ARM has released their next generation architecture ARMv9, which will set the course of the industry for a decade. It is thus a very significant event that deserves some scrutiny.

There are many items to talk about here, but to me the big topic is the standardization on what is called the Scalable Vector Extension 2 (SVE2). You have probably heard about SIMD instruction-sets such as MMX, SSE2, AVX, AVX-512 from Intel or the older Neon from ARM. However, you might not know exactly what these are for, other than in a superficial sense. I will try to explain what makes SVE/SVE2 so different from these older SIMD instruction-sets.

And did you know that Fujitsu has played a significant role in all of this? We are seeing a sort of return to old-school super-computing as found in the Cray-1 super computers from decades ago. The Cray company is in fact not dead yet, but is actually busy building ARM based super-computers: LRZ to Deploy HPE’s Cray CS500 System with Arm Fujitsu A64FX Processors.

The Cray-1 supercomputer, c. 1976. It was approximately 6 feet high and 7 feet in diameter (1.8 by 2.1 metres).

Is ARMv9 a Physical Chip I Can Buy in the Store?

This isn’t the same as when AMD or Intel release a new microprocessor that you can buy and stick in your PC to get higher performance. It is not a physical thing. Rather, this is a new microprocessor architecture, backwards compatible with previous ARM architectures such as ARMv8.

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Geek dad, living in Oslo, Norway with passion for UX, Julia programming, science, teaching, reading and writing.