4 ms·

It is aimed at a completely different market from RISC-V. RISC-V advantages is that it is an incredible simple and extensible architecture aimed at low power /

It is aimed at a completely different market from RISC-V. RISC-V advantages is that it is an incredible simple and extensible architecture aimed at low power / embedded use cases. It is also easy to customize (similar to ARM) for specific use cases. Power ISA is a super computer chip, while RISC-like, has a lot of legacy baggage and isn't designed for low-power nor is it designed for embedded situations. It also is not designed for customizability, it is more like a monolith project. Power ISA will have space at the top of the market for very high performance CPUs. But I think it will be stuck there as there are no benefits over RISC-V in the areas where RISC-V is growing right now.

orbifold 1y ago
That isn’t actually true. I‘ve personally worked on an embedded POWER processor https://github.com/electronicvisions/nux https://github.com/electronicvisions/nux. It is used as a dual core embedded micro-controller in a neuromorphic chip. Each core has just 16kB of memory on chip and 4kB instruction cache. POWER has subsets of the instruction set which have a gcc and llvm target and are well suited for embedded use cases. Main advantage of RISCV at this point is that it has a larger community. But at the time it didn’t even have a vector instruction set, whereas we could easily modify the POWER one for our purposes.
panick21_ 1y ago
RISC-V is absolutely not and never has been 'aimed at low power / embedded'. Literally from the very beginning the target was 'be an ISA for everything'. Its just natural that simpler things were standardized first and came to market first. That POWER is better at top of the market is highly questionable, every new startup coming into the high performance space has universally picked RISC-V over OpenPOWER. Also, nowadays even complex ISA were fine for embedded. The cost difference for stuff like that is tiny. Its really just about how many options do you have in the market, both open and closed. And that's where RISC-V by now simply has more. OpenPOWER was only fake open for a long time, while marketing itself as open. Only when they were totally getting crushed, did they update and are more like RISC-V, but it was many years to late.
- bhouston 1y ago
  > Its just natural that simpler things were standardized first and came to market first. Which isn't that different than what I am saying. RISC-V is marketing towards low-power/embedded right now because it doesn't have performant cores. https://benhouston3d.com/blog/risc-v-in-2024-is-slow https://benhouston3d.com/blog/risc-v-in-2024-is-slow Power ISA was not focused on this market, its historical market was high performance computing.
  - dragontamer 1y ago
    Freescale PowerQUICC fans say whaaaaaat? Power ISA absolutely was used in embedded contexts for years. Decades even. --------- Instruction sets aren't very important actually. Like yeah, compiler infrastructure helps but a lot of embedded decision making is about peripherals. PowerQUICC had powerful and extendable I/O that could be customized to many different needs. And I believe the bulk of those benefits stay over to the updated ARM chip QorIQ (as NXP bought FreeScale and seems to have prioritized ARM).
    - adrian_b 1y ago
      After Motorola has abandoned totally (MC88k, M.core) or partially (MC68k => Coldfire) its older ISAs and it has transitioned to using the POWER/PowerPC ISA, it has applied it to the market in which they was interested, designing many kinds of microcontrollers with it, mainly for the automotive and communications markets, where microcontrollers with higher performance were required. Around the same time IBM has also introduced a series of microcontrollers based on the POWER ISA (PowerPC 4xx). However, when the POWER ISA has initially been designed, before its launch in 1990, its target were high-end scientific workstations and servers made by IBM. The idea of using it in embedded computers has come much later, when the increased density achievable in integrated circuits has made that possible.
      - dragontamer 1y ago
        Sure. But the embedded PowerQUICC chips were in use between the years 199x and 201x, and are still manufactured today in 2025. My overall point is that Power ISA has a long history as both high performance compute AND embedded (be it industrial, automotive, or space embedded). Maybe in the late 1980s POWER was high performance only. But there's a big history here and it's weird to see this discussion ignore Power ISA's long embedded history. ------- Does OpenPower have a chance today? I dunno. Obviously the hype is in RISC-V and maybe a bit of ARM. But it's not a bad ISA and Power used to target embedded not very long ago
snvzz 1y ago
>It is aimed at a completely different market from RISC-V. Not possible. RISC-V is aimed at absolutely everything. Thus leaving no sizable niche exclusive to POWER ISA.

orbifold 1y ago

That isn’t actually true. I‘ve personally worked on an embedded POWER processor https://github.com/electronicvisions/nux https://github.com/electronicvisions/nux. It is used as a dual core embedded micro-controller in a neuromorphic chip. Each core has just 16kB of memory on chip and 4kB instruction cache. POWER has subsets of the instruction set which have a gcc and llvm target and are well suited for embedded use cases. Main advantage of RISCV at this point is that it has a larger community. But at the time it didn’t even have a vector instruction set, whereas we could easily modify the POWER one for our purposes.

panick21_ 1y ago

RISC-V is absolutely not and never has been 'aimed at low power / embedded'. Literally from the very beginning the target was 'be an ISA for everything'. Its just natural that simpler things were standardized first and came to market first. That POWER is better at top of the market is highly questionable, every new startup coming into the high performance space has universally picked RISC-V over OpenPOWER. Also, nowadays even complex ISA were fine for embedded. The cost difference for stuff like that is tiny. Its really just about how many options do you have in the market, both open and closed. And that's where RISC-V by now simply has more. OpenPOWER was only fake open for a long time, while marketing itself as open. Only when they were totally getting crushed, did they update and are more like RISC-V, but it was many years to late.

bhouston 1y ago
> Its just natural that simpler things were standardized first and came to market first. Which isn't that different than what I am saying. RISC-V is marketing towards low-power/embedded right now because it doesn't have performant cores. https://benhouston3d.com/blog/risc-v-in-2024-is-slow https://benhouston3d.com/blog/risc-v-in-2024-is-slow Power ISA was not focused on this market, its historical market was high performance computing.
- dragontamer 1y ago
  Freescale PowerQUICC fans say whaaaaaat? Power ISA absolutely was used in embedded contexts for years. Decades even. --------- Instruction sets aren't very important actually. Like yeah, compiler infrastructure helps but a lot of embedded decision making is about peripherals. PowerQUICC had powerful and extendable I/O that could be customized to many different needs. And I believe the bulk of those benefits stay over to the updated ARM chip QorIQ (as NXP bought FreeScale and seems to have prioritized ARM).
  - adrian_b 1y ago
    After Motorola has abandoned totally (MC88k, M.core) or partially (MC68k => Coldfire) its older ISAs and it has transitioned to using the POWER/PowerPC ISA, it has applied it to the market in which they was interested, designing many kinds of microcontrollers with it, mainly for the automotive and communications markets, where microcontrollers with higher performance were required. Around the same time IBM has also introduced a series of microcontrollers based on the POWER ISA (PowerPC 4xx). However, when the POWER ISA has initially been designed, before its launch in 1990, its target were high-end scientific workstations and servers made by IBM. The idea of using it in embedded computers has come much later, when the increased density achievable in integrated circuits has made that possible.
    - dragontamer 1y ago
      Sure. But the embedded PowerQUICC chips were in use between the years 199x and 201x, and are still manufactured today in 2025. My overall point is that Power ISA has a long history as both high performance compute AND embedded (be it industrial, automotive, or space embedded). Maybe in the late 1980s POWER was high performance only. But there's a big history here and it's weird to see this discussion ignore Power ISA's long embedded history. ------- Does OpenPower have a chance today? I dunno. Obviously the hype is in RISC-V and maybe a bit of ARM. But it's not a bad ISA and Power used to target embedded not very long ago

snvzz 1y ago

>It is aimed at a completely different market from RISC-V. Not possible. RISC-V is aimed at absolutely everything. Thus leaving no sizable niche exclusive to POWER ISA.