3 ms·

There's a lot of "what" in the article, not so much "why" or "history". Every decade or so, someone tries an open, current technology and specs CPU. Plenty of

by VLM 7y ago

There's a lot of "what" in the article, not so much "why" or "history". Every decade or so, someone tries an open, current technology and specs CPU. Plenty of free FOSS or FOSS-like z80 or 6502 cores out there, not so many cutting edge designs. The key differentiator with RISC-V is its pretty near cutting edge compared to every other free core out there. There are tons of cores out there for FPGAs but usually they are not cutting edge powerful (although close...) and they always have interesting and expensive licensing for non-trivial use. RISC-V should, once community support and toolchains catch up, eat every licensing dollar currently being spent on Xylinx Microblaze or Intel/Altera NIOS-II. So there's money laying around interested in RISC-V. Or a more negative way of looking at it is there's a lot of money thats interested in not seeing RISC-V succeed. Around the turn of the century, the same idea was OpenSPARC. Around last decade, the same idea was OpenPOWER. Now, its RISC-V and ... maybe its going to be a winner? Its about time.

floatboth 7y ago
POWER actually became a royalty-free ISA very very recently, way after the initial RISC-V hype. When the term OpenPOWER was introduced, it was mostly about the ecosystem – open standards for boot/ABI/etc, openness to board makers (hello Raptor), open firmware and so on. BTW: RISC-V being a royalty-free ISA does not mean every implementation is gonna be open source. Though it seems like SiFive's implementation is.
zozbot234 7y ago
> The key differentiator with RISC-V is its pretty near cutting edge compared to every other free core out there. I thought it was an express goal of RISC-V to not depend on cutting-edge features in the ISA, in order to avoid the IP issues that constrain most other architectures, and also to keep basic implementations simple enough for e.g. educational use. Although RISC-V also puts quite a bit of emphasis on being open to extensibility, which requires some extra attention in e.g. making efficient use of the ISA encoding space.
leggomylibro 7y ago
It's also less vulnerable to global trade conflicts. A royalty-free license means that you don't have to depend on a company like ARM for your CPU design. For example, if you're a Chinese manufacturer who relies on STM32 chips with their ARM Cortex-M cores and you're worried about the winds of global trade, what do you do? It looks like you make a new line of RISC-V chips with the same memory and peripheral layout. Problem solved: https://www.gigadevice.com/products/microcontrollers/gd32/risc-v/ https://www.gigadevice.com/products/microcontrollers/gd32/ri... And as a consequence, civilians who live in heavily-sanctioned places like Iran can also learn about modern embedded computing more easily on a budget. The economic incentives to produce actual hardware brings the ISA out of FPGA-land, which can improve equality of access and opportunity around the world. It might also help that the ISA is designed in a modular way so that it can be suitable for everything from small microcontrollers to large-scale application processors.
TomVDB 7y ago
> RISC-V should ... eat every licensing dollar currently being spent on Xylinx Microblaze or Intel/Altera NIOS-II. So, in the grand scheme of things, about $0? Small Microblaze and Nios-II cores come for free. Their larger versions are available for a token license fee. (TBH, I don't know why they even bother...)
ken 7y ago
The big difference this time around is that a lot of us no longer need cutting edge CPU performance. The CPU in my home computer is over 10 years old, and I see no need to upgrade for performance. A fast 2010-era CPU is still pretty darn good for a lot of common uses. That was definitely not the case at the turn of the century. In 2000, a new personal computer might have had a Pentium 4 or PowerPC G4, while in 1990 it had an 80486 or 68030 -- a huge performance difference. You couldn't even run a 2000-era OS (except Linux) on a 1990 CPU, and you wouldn't have wanted to if you could. I don't know much about RISC-V, but even if it's 10 years behind the state of the art, that sounds good to me!

by VLM 7y ago

floatboth 7y ago

POWER actually became a royalty-free ISA very very recently, way after the initial RISC-V hype. When the term OpenPOWER was introduced, it was mostly about the ecosystem – open standards for boot/ABI/etc, openness to board makers (hello Raptor), open firmware and so on. BTW: RISC-V being a royalty-free ISA does not mean every implementation is gonna be open source. Though it seems like SiFive's implementation is.

zozbot234 7y ago

> The key differentiator with RISC-V is its pretty near cutting edge compared to every other free core out there. I thought it was an express goal of RISC-V to not depend on cutting-edge features in the ISA, in order to avoid the IP issues that constrain most other architectures, and also to keep basic implementations simple enough for e.g. educational use. Although RISC-V also puts quite a bit of emphasis on being open to extensibility, which requires some extra attention in e.g. making efficient use of the ISA encoding space.

leggomylibro 7y ago

It's also less vulnerable to global trade conflicts. A royalty-free license means that you don't have to depend on a company like ARM for your CPU design. For example, if you're a Chinese manufacturer who relies on STM32 chips with their ARM Cortex-M cores and you're worried about the winds of global trade, what do you do? It looks like you make a new line of RISC-V chips with the same memory and peripheral layout. Problem solved: https://www.gigadevice.com/products/microcontrollers/gd32/risc-v/ https://www.gigadevice.com/products/microcontrollers/gd32/ri... And as a consequence, civilians who live in heavily-sanctioned places like Iran can also learn about modern embedded computing more easily on a budget. The economic incentives to produce actual hardware brings the ISA out of FPGA-land, which can improve equality of access and opportunity around the world. It might also help that the ISA is designed in a modular way so that it can be suitable for everything from small microcontrollers to large-scale application processors.

TomVDB 7y ago

> RISC-V should ... eat every licensing dollar currently being spent on Xylinx Microblaze or Intel/Altera NIOS-II. So, in the grand scheme of things, about $0? Small Microblaze and Nios-II cores come for free. Their larger versions are available for a token license fee. (TBH, I don't know why they even bother...)

ken 7y ago

The big difference this time around is that a lot of us no longer need cutting edge CPU performance. The CPU in my home computer is over 10 years old, and I see no need to upgrade for performance. A fast 2010-era CPU is still pretty darn good for a lot of common uses. That was definitely not the case at the turn of the century. In 2000, a new personal computer might have had a Pentium 4 or PowerPC G4, while in 1990 it had an 80486 or 68030 -- a huge performance difference. You couldn't even run a 2000-era OS (except Linux) on a 1990 CPU, and you wouldn't have wanted to if you could. I don't know much about RISC-V, but even if it's 10 years behind the state of the art, that sounds good to me!