Why Apple is preparing to (partially) abandon ARM for RISC-V

After PowerPC and x86 in PCs, Apple would be working to replace ARM. The firm would begin work by substituting small ARM microcontroller cores for their equivalent using the RISC-V instruction set. A conversion that will go slowly, but surely. And that seems logical given the American giant’s thirst for technological independence.

Is Apple taking a step closer to total technological autonomy? This is what the SemiAnalysis publication believes, which explains in a newsletter that the brand’s engineers are in the process of migrating ARM cores from its chips to the RISC V open microarchitecture. Don’t get carried away, we don’t not talking here about the chip’s powerful calculation cores. But of the horde of subservient little cores and other microcontrollers that dot the logic blocks of various SoCs – the Watch might be the first to rock.

As in any information where the interested party (Apple) will not make any comment, it is necessary to be interested in the source. In this case, Dylan Patel, an analyst who publishes a largely paid, highly researched and reliable newsletter called “SemiAnalysis”. In his letter of 9/16/2022, Mr Patel has a very assertive tone. Focusing on projects that demonstrate RISC-V adoption, the article says, “ SemiAnalysis is able to confirm that these cores (ARM dedicated to menial functions) are being converted to RISC-V for future generations of chips “. For the time being, we are talking here about “non-facing users” cores. That is to say, it’s not about the cores in charge of the applications that users manipulate… but about the horde of small microcontroller-like cores that swarm in SoCs.

But that’s just the beginning, because RISC-V is taking off. In all parts of the industry.

RISC-V: the sense of history for the industry, a no-brainer for Apple

Apple is a company that likes to control everything. The company did not hesitate to change processor architecture several times for its computers (Power PC, then x86, then ARM). To succeed in arriving at chips, both fixed and mobile, where it masters not only the production subcontractor (currently TSMC), but also the design of CPU and GPU cores (custom cores thanks to its “Architect” license).

Read also: RISC-V: ARM’s competing architecture passes the 5nm engraving milestone

The only thing that no company designing ARM chips knows is the instruction set (ISA, for statement set architecture). If Apple can do what it wants with its cores, it does so within the limits of the instructions developed by ARM. RISC-V, by contrast, is developed by a foundation that defines the standard, but does not impose a license for use. And allows – with a lot of internal work – everyone to develop their own homemade instructions if they want (and if they manage with it!). While guaranteeing community development, which makes it possible to rely on permanent improvements, unlike dying architectures (PowerPC, SPARC, etc.).

Read also: RISC-V, ARM’s rival, will get its first GPU (and it’s far from being a detail)

For Apple, there is a growing maturity story of RISC-V, which is not only powering hard drives (Seagate) but also getting ready to go into space – future ESA and NASA flight computers – or driving our cars. But there are also important events that have undoubtedly had a catalytic effect on the projects in progress and the “leakage” of this information.

AMR: Nvidia takeover, bad Qualcomm/Nuvia messages

Danby, James Francis; Ship on Fire; Tameside Museums and Galleries Service: The Astley Cheetham Art Collection; http://www.artuk.org/artworks/ship-on-fire-89313

The attempted takeover of ARM by Nvidia had the effect of an earthquake in the industry. Even if it resulted in a refusal by the competition authorities a little more than a year after its implementation, it was undoubtedly an accelerator for RISC-V. All the big names in chips, from Qualcomm to MediaTek, via STMicro, Apple or Texas Instruments have been able to measure the threat. Could ARM, which until then had been the “Switzerland of semi-conductors”, find itself controlled by a competing company? Impossible !

The Nvidia episode must have had a very particular echo for Apple, which ceased all work with Nvidia after two generations of GPUs which overheated in its Macbooks. A “case” that led to massive recalls of machines. And which would have given rise, behind the scenes, to stormy conversations between the two directions. The rest of the story is known: after that, Apple never worked with the GPU champion again and preferred to cooperate with AMD – just like Microsoft for its Xbox 360/One/Series (formerly under Nvidia chips) or Sony for its PlayStation 4/5 (which only called on Nvidia for the PS3).

Read also: Why Qualcomm hasn’t (yet) announced competing chips to Apple’s M1s

Another “case” is to strengthen the position of Apple engineers in their work around RISC-V. That of the legal attack on Qualcomm by ARM, which refuses that the company uses ARM CPU cores developed by Nuvia, which Qualcomm bought almost two years ago. If we don’t know all the legal reasons – license? – a rough vision of the case can be turned as follows: even if you develop or buy custom ARM core technologies, the ARM entity can mess with you. The kind of stuff that nobody likes.

And even less to Apple.

Just as Apple’s move from x86 to ARM has been talked about for years, converting different ARM cores to RISC-V is going to take time. RISC-V is far from being as mature as ARM, the first uses should target low power cores. If Apple can introduce cores quietly within its different SoCs, one can quite imagine heterogeneous chips, its ARM CPU cores being among the most efficient in the world. But it is quite likely that in the medium term, if the development of RISC-V continues at the current speed, that Apple will one day totally evacuate ARM. And then she will be really in control of her fleas.

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