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Apple M1 foreshadows Rise of RISC-V

date May 28, 2021
authors Erik Engheim
reading time 1 min

Changes

Moore’s Law

They saw how the end of Moore’s Law meant that you could no longer easily squeeze more performance out of general purpose CPU cores. You needed specialized hardware: Coprocessors.

Speed

We are stuck on close to 3–5 GHz. Go higher and Watt consumption and heat generation goes through the roof. However we are able to add a lot more transistors. We simply cannot make the transistors work faster.

RISC-V Advantages

Low number of instructions

This is exactly what RISC-V got designed for. It has a bare minimum instruction-set of about 40–50 instructions which lets it do all the typical CPU stuff. It may sound like a lot, but keep in mind that an x86 CPU has over 1500 instructions.

Using less silicon

The small and simple instruction-set of RISC-V makes it possible to implement RISC-V cores in much less silicon than ARM.

Future: Arm + RISC-V

Processor + Coprocessors

Every coprocessor will be different. It will thus contain a RISC-V processor to manage things which implements the core instruction-set as well as an extension instruction-set tailor made for what that co-processor needs to do.

ARM Processor + RISC-V Coprocessors

Ironically we may see a future where Macs and PCs are powered by ARM processors. But where all the custom hardware around them, all their coprocessors will be dominated by RISC-V. As coprocessor get more popular more silicon in your System-on-a-Chip (SoC) may be running RISC-V than ARM.

ARM + RISC-V, not ARM or RISC-V

I though the future would be about ARM or RISC-V. Instead it will likely be ARM and RISC-V.

Combining general purpose + specialized tasks

General purpose ARM processors will be at the center with an army of RISC-V powered coprocessors accelerating every possible task from graphics, encryption, video encoding, machine learning, signal processing to processing network packages.