7 ms·

i thought risc-v is >10years "old". how long is an ISA "very new"?

by daef 2y ago

rbanffy 2y ago
x86 is more than 40. ARM is 30-ish. Most importantly, it's been just a few years since we could start getting reasonable RISC-V boards.
- Someone 2y ago
  and one likely reason the boards weren’t there was (https://en.wikipedia.org/wiki/RISC-V#Design https://en.wikipedia.org/wiki/RISC-V#Design): “As of June 2019, version 2.2 of the user-space ISA[46] and version 1.11 of the privileged ISA[3] are frozen, permitting software and hardware development to proceed. The user-space ISA, now renamed the Unprivileged ISA, was updated, ratified and frozen as version 20191213” So, it’s more like 5 years old, compared to ≈40 for 32-bit x86, ≈20 for 64-bit x86.
  - snvzz 2y ago
    December 2021, for the specs required by RVA22 which the P550 implements. P550 was announced shortly after these specs were ratified, so it's one of the earliest RVA22 designs. I am expecting there'll be others we will get to see this year.
- RobotToaster 2y ago
  First ARM processor was 1985, so 40 years almost exactly.
- klelatti 2y ago
  I think it’s a bit problematic to say ARM is 30-ish years old. The company is 34 years old but 64 bit Arm (AArch64) which is really very different to its predecessors was announced in 2011 so arguably only 14 years old.
  - K0balt 2y ago
    I’m pretty sure the IP/experience transfer to arch64 was massive compared to starting for scratch.
    - klelatti 2y ago
      So PowerPC is 70 years old because IBM was designing computers in 1954? :)
      - K0balt 2y ago
        Yes, in a sense. But that is not an apt comparison at all, really. ISA design is a complex endeavor. Arch64 benefited from multiple factors directly attributable to ARMs prior art, domain knowledge, and market positioning. There is a huge distinction between a globally recognized and dominant ISA engineering firm coming out with a “new” ISA that their engineers had been prepping for for years, and the effort required to create a novel ISA and ecosystem from scratch. One is just another day at the office, while the other is a very riscy endeavor that requires amassing the talent, creating incentives, creating an engineering culture, and trying to create a niche in a market that was arguably fully populated by other options. And then, you still have to create an entire family of ISAs to match various specification levels. It’s not an apples to apples comparison.
        klelatti 2y ago
        Hmmm. I didn’t make any comparison. I just pointed out that AArch64 isn’t 30 odd years old.
        K0balt 2y ago
        Well, that is definitely true. I guess that the quibble is with the assumption of equivalence…. (which you didn’t explicitly state, so I apologize for thinking it that way) ….of the launching of arch64 with the launching of the RiscV ISA. They were both theoretically clean slate designs, but one was made by a bunch of academics and the other by a company with decades of ISA design expertise. I’d expect the latter to be much, much more mature, all other things being equal. At any rate, what riscV really did so far was to make 8bit MCUs irrelevant. I used to use a lot of 8 bit parts even with M0 around, but now with chips like the CH32v003 and family, it’s just ridiculous to even contemplate. I mean you can hook up an 8pin MCU and a couple of resistors to a vga monitor and a keyboard and have a a computer in a heat shrink tube that walks circles around my ancient apple II for $0.60. And if you want WiFi, BLE, and some other wireless stuff, with 3x the speed and 100x the memory, the riscV esp32 chips come in at about $1, and they can do pretty strong edge AI. It’s all just silly at this point, and it’s riscV that caused that sea change.
beeflet 2y ago
This same point is made in threads discussing how wayland protocol is 16 years "old". I think it's different if the system starts out as a research project rather than a commercial project, because the time until a usable implementation is much greater. For example, I would say that riscv is "newer" than loongISA/loongarch despite being slightly older in a literal sense. If you look at an arch like x86 or ARM it was designed right before chips were released, and then extended over time. The same goes for the X protocol, it simply extended previous versions. If you are designing something from the ground up to avoid the inherent problems of an existing system, it is reasonable to take time and research design problems to make sure you don't recreate the same issues (which would defeat the point of the redesign). It doesn't compete on the same time-frame as an extension of an existing system.
formerly_proven 2y ago
Privileged spec is only a couple years old and mainline Linux only runs on RISC-V since 2022 or something like that.
snvzz 2y ago
>i thought risc-v is >10years "old". September 2019 for the base specs being ratified. But even that isn't the true starting gun for anything but basic MCU.. For high performance, it's RVA22. The relevant specs were only ratified in December 2021. It takes 3 years from IP to chips, and thus we are seeing the first RVA22 chips now. No surprises there.

i thought risc-v is >10years "old". how long is an ISA "very new"?

by daef 2y ago

i thought risc-v is >10years "old". how long is an ISA "very new"?

x86 is more than 40. ARM is 30-ish. Most importantly, it's been just a few years since we could start getting reasonable RISC-V boards.

Someone 2y ago
and one likely reason the boards weren’t there was (https://en.wikipedia.org/wiki/RISC-V#Design https://en.wikipedia.org/wiki/RISC-V#Design): “As of June 2019, version 2.2 of the user-space ISA[46] and version 1.11 of the privileged ISA[3] are frozen, permitting software and hardware development to proceed. The user-space ISA, now renamed the Unprivileged ISA, was updated, ratified and frozen as version 20191213” So, it’s more like 5 years old, compared to ≈40 for 32-bit x86, ≈20 for 64-bit x86.
- snvzz 2y ago
  December 2021, for the specs required by RVA22 which the P550 implements. P550 was announced shortly after these specs were ratified, so it's one of the earliest RVA22 designs. I am expecting there'll be others we will get to see this year.
RobotToaster 2y ago
First ARM processor was 1985, so 40 years almost exactly.
klelatti 2y ago
I think it’s a bit problematic to say ARM is 30-ish years old. The company is 34 years old but 64 bit Arm (AArch64) which is really very different to its predecessors was announced in 2011 so arguably only 14 years old.
- K0balt 2y ago
  I’m pretty sure the IP/experience transfer to arch64 was massive compared to starting for scratch.
  - klelatti 2y ago
    So PowerPC is 70 years old because IBM was designing computers in 1954? :)
    - K0balt 2y ago
      Yes, in a sense. But that is not an apt comparison at all, really. ISA design is a complex endeavor. Arch64 benefited from multiple factors directly attributable to ARMs prior art, domain knowledge, and market positioning. There is a huge distinction between a globally recognized and dominant ISA engineering firm coming out with a “new” ISA that their engineers had been prepping for for years, and the effort required to create a novel ISA and ecosystem from scratch. One is just another day at the office, while the other is a very riscy endeavor that requires amassing the talent, creating incentives, creating an engineering culture, and trying to create a niche in a market that was arguably fully populated by other options. And then, you still have to create an entire family of ISAs to match various specification levels. It’s not an apples to apples comparison.
      - klelatti 2y ago
        Hmmm. I didn’t make any comparison. I just pointed out that AArch64 isn’t 30 odd years old.
        K0balt 2y ago
        Well, that is definitely true. I guess that the quibble is with the assumption of equivalence…. (which you didn’t explicitly state, so I apologize for thinking it that way) ….of the launching of arch64 with the launching of the RiscV ISA. They were both theoretically clean slate designs, but one was made by a bunch of academics and the other by a company with decades of ISA design expertise. I’d expect the latter to be much, much more mature, all other things being equal. At any rate, what riscV really did so far was to make 8bit MCUs irrelevant. I used to use a lot of 8 bit parts even with M0 around, but now with chips like the CH32v003 and family, it’s just ridiculous to even contemplate. I mean you can hook up an 8pin MCU and a couple of resistors to a vga monitor and a keyboard and have a a computer in a heat shrink tube that walks circles around my ancient apple II for $0.60. And if you want WiFi, BLE, and some other wireless stuff, with 3x the speed and 100x the memory, the riscV esp32 chips come in at about $1, and they can do pretty strong edge AI. It’s all just silly at this point, and it’s riscV that caused that sea change.

beeflet 2y ago

This same point is made in threads discussing how wayland protocol is 16 years "old". I think it's different if the system starts out as a research project rather than a commercial project, because the time until a usable implementation is much greater. For example, I would say that riscv is "newer" than loongISA/loongarch despite being slightly older in a literal sense. If you look at an arch like x86 or ARM it was designed right before chips were released, and then extended over time. The same goes for the X protocol, it simply extended previous versions. If you are designing something from the ground up to avoid the inherent problems of an existing system, it is reasonable to take time and research design problems to make sure you don't recreate the same issues (which would defeat the point of the redesign). It doesn't compete on the same time-frame as an extension of an existing system.

formerly_proven 2y ago

Privileged spec is only a couple years old and mainline Linux only runs on RISC-V since 2022 or something like that.

snvzz 2y ago

>i thought risc-v is >10years "old". September 2019 for the base specs being ratified. But even that isn't the true starting gun for anything but basic MCU.. For high performance, it's RVA22. The relevant specs were only ratified in December 2021. It takes 3 years from IP to chips, and thus we are seeing the first RVA22 chips now. No surprises there.