I have been following RISC-V for many years, and I am enamoured with the goal of an open source chip ISA & hardware. Unfortunately all the RISC-V dev boards have been prohibitively expensive, so I have kept aware of the platform but haven’t invested much more effort than that.

However last week SiFive announced a new dev board at a cost less than 1/4 of the original board + expansion. This has enticed me back into the ecosystem and the opportunities here.

What is RISC-V?

Lets back up for a moment, why am I so excited about this platform?

Currently for many projects, it isn’t worth spending time and money on custom silicon, as it is just too cost prohibitive. While there are existing chip designs available for licensing (x86, ARM), the licensing fees, NDAs, and lead times make it not worth it. What this boils down to, it is currently too expensive to custom fabricate your own tailored chips.
Vecause of this, most companies currently just use what is available off the shelf. As it is cheaper to just use an existing COTS chip (Common Off The Shelf), as the economics and time to market just make it easier. Even if that existing COTS chip is overkill, has additional power draw, has unneeded features, etc.

RISC-V is an open source ISA that can be used to create open hardware microprocessors. You are able to use pre-defined designs, modify to create new custom chips with just the subset of features you require, with a reduced lead time. The advantage of using an open community supported ISA, is that there is an entire ecosystem of buildchains, libraries, OS, etc that will support your chip.

RISC-V is going to shake up a lot of industries and create new startup opportunities. Industries will be able to create smaller, optimised, feature reduced chips that target exactly the use case they are targetting.
For example, Western Digital have announced that all their hard drives will be utilising RISC-V chips, and they talk of the potential of it https://www.westerndigital.com/company/innovations/risc-v

Why am I interested in RISC-V?
For me personally, I am excited for the fully open stack opportunities in a decentralised web.
For me professionally, this will have a large impact on the industries I am working with.

We have the opportunity to create a completely free and open source stack all the way from silicon, hardware, OS, and application stack.

Introductory videos

Complete beginner overview: If you know nothing at all about RISC-V then Linus has an very beginners intro to what the opportunities are.

[YouTube] [IPFS mirror]

More technical overview: If you have any knowledge of CPUs then this is probably a better intro video.

[YouTube] [IPFS mirror]

Opportunities for customisation: This video dives into the types of extensions you can use to optimise the chips for power draw, or acceleration (like ML). Shows the flexibility of design

[YouTube] [IPFS mirror]

Chip designer

If you want to play around, you can design your own custom RISC-V chip. Tweak the number of cores, cache, capabilities, etc. https://scs.sifive.com/core-designer/

SiFive chip designer

RISC-V development boards

The previous development board cost a total of US$3,000 for the base board + Expansion board to give you the ability USB, PCI-E slots, etc. This was just too far out of my price range and is why I waited for later revisions.

SiFive unleashed devboard SiFive unleashed devboard and expansion

Latest development board

Which brings us to the latest development board:

SiFive unmatched devboard

It now has 4x SiFive U74 cores (general purpose), and 1x SiFive S7 core (real time). 8GB integrated ram, 2x m.2 slots (M-Key for bluetooth/wifi, E-Key for NVME). x16 PCI-E for graphics card. Mini-ITX form factor so it can be mounted in a standard PC case, etc etc. And most importantly is that reduced price.

More articles on the hardware

It is still expensive for a development board that will be roughly speed of a Raspberry Pi 4. But it does have all those expansion slots, and is supporting further development.

What are my plans for RISC-V?

I plan on pre-ordering the new SiFive development board. I would like to experiment and write up my experiences using it for projects like:

  • Getting decentralised tech running on the hardware (IPFS + Ethereum)
  • Have my blog run on a COMPLETELY open stack. All the way up from the silicon, OS, dev tools, Jekyll, IPFS, etc.
  • Get .Net 5.0 running on it
  • Program the real time S7 core
  • Using RISC-V in IoT scenarios
  • Having it integrate with Azure
  • etc.