5 ms·

Now the clock begins on Apple switching to RISC-V

ridiculous_fish 4y ago
A Tom's Hardware piece about the possibility: https://www.tomshardware.com/news/apple-looking-for-risc-v-programmers https://www.tomshardware.com/news/apple-looking-for-risc-v-p... I speculate this is somewhat less likely now that the NVidia / ARM deal has fallen through but surely Apple wants the option at least.
- senttoschool 4y ago
  It's not going to happen. Apple probably already use RISC-V designs somewhere in their hardware stack. But the ISA will remain ARM for a long long time. Even Apple Silicon has a ton of stock ARM cores to control various SoC tasks.
NobodyNada 4y ago
This seems very, very unlikely to me. RISC-V is a very similar architecture to AArch64; I haven't heard a reason to expect it to have improved performance or efficiency. (Its only distinguishing feature (that I know of) is compressed instructions -- which ARM used to have (THUMB mode) before dropping support in AArch64, so presumably it doesn't help on Apple's systems with their huge caches and high memory bandwidth.) Rather, RISC-V's primary advantage over ARM is its openness; vendors can do whatever they want with the ISA without having to pay license fees or maintain compatibility. But this doesn't affect Apple at all; they co-founded ARM, and they have a huge amount of influence over the direction of the architecture along with some sort of special license that allows them to do things other CPU vendors aren't allowed to do (https://news.ycombinator.com/item?id=29782840 https://news.ycombinator.com/item?id=29782840, https://twitter.com/stuntpants/status/1346470705446092811 https://twitter.com/stuntpants/status/1346470705446092811). Developing an entirely new high-end CPU mircoarchitecture takes many years and many billions of dollars. It's not something Apple's going to do unless they have a very, very good reason -- and RISC-V being really cool is unfortunately not a good enough reason.
- keepquestioning 4y ago
  Apple will not have to pay ARM for licensing
  - stu2b50 4y ago
    Apple doesn't pay ARM for licensing.
    - senttoschool 4y ago
      Even if Apple does, it's probably peanuts. Apple has invested billions to make a full transition to ARM. I'd think that they would have to spend at least $50 billion or more to redesign all the Apple Silicon from the iPhone to the Mac Pro, rewrite 5 or 6 operating systems, and beg developers to recompile their apps. It'd be a nightmare. I think Apple will stay on ARM for at least 20 years...
      - deleted 4y ago
        [deleted]
      - desiarnezjr 4y ago
        Why just 20 years? This direction gives full control of a silicon roadmap. They can make it whatever they want or need. My guess is they have a more specific roadmap than even Intel or AMD at this point, as they're not commodity processors, but now engineered for a very specific purpose.
- FullyFunctional 4y ago
  I agree, it’s seems unlikely they will have another transition as they now control their own destiny. The fact that Arm64 doesn’t have compressed instructions is obviously a very deliberate choice, thus I can’t agree with the notion that RISC-V compressed instructions could be a potential “advantage” over Arm64. Their absence is a massive advantage in many ways that I have explained over and over on HN and it’s the single biggest stupidity in RISC-V for high-end perf (not microcontrollers).
- 4y ago
internet_user 4y ago
5 years?

A Tom's Hardware piece about the possibility: https://www.tomshardware.com/news/apple-looking-for-risc-v-programmers https://www.tomshardware.com/news/apple-looking-for-risc-v-p... I speculate this is somewhat less likely now that the NVidia / ARM deal has fallen through but surely Apple wants the option at least.

senttoschool 4y ago
It's not going to happen. Apple probably already use RISC-V designs somewhere in their hardware stack. But the ISA will remain ARM for a long long time. Even Apple Silicon has a ton of stock ARM cores to control various SoC tasks.

NobodyNada 4y ago

This seems very, very unlikely to me. RISC-V is a very similar architecture to AArch64; I haven't heard a reason to expect it to have improved performance or efficiency. (Its only distinguishing feature (that I know of) is compressed instructions -- which ARM used to have (THUMB mode) before dropping support in AArch64, so presumably it doesn't help on Apple's systems with their huge caches and high memory bandwidth.) Rather, RISC-V's primary advantage over ARM is its openness; vendors can do whatever they want with the ISA without having to pay license fees or maintain compatibility. But this doesn't affect Apple at all; they co-founded ARM, and they have a huge amount of influence over the direction of the architecture along with some sort of special license that allows them to do things other CPU vendors aren't allowed to do (https://news.ycombinator.com/item?id=29782840 https://news.ycombinator.com/item?id=29782840, https://twitter.com/stuntpants/status/1346470705446092811 https://twitter.com/stuntpants/status/1346470705446092811). Developing an entirely new high-end CPU mircoarchitecture takes many years and many billions of dollars. It's not something Apple's going to do unless they have a very, very good reason -- and RISC-V being really cool is unfortunately not a good enough reason.

keepquestioning 4y ago
Apple will not have to pay ARM for licensing
- stu2b50 4y ago
  Apple doesn't pay ARM for licensing.
  - senttoschool 4y ago
    Even if Apple does, it's probably peanuts. Apple has invested billions to make a full transition to ARM. I'd think that they would have to spend at least $50 billion or more to redesign all the Apple Silicon from the iPhone to the Mac Pro, rewrite 5 or 6 operating systems, and beg developers to recompile their apps. It'd be a nightmare. I think Apple will stay on ARM for at least 20 years...
    - deleted 4y ago
      [deleted]
    - desiarnezjr 4y ago
      Why just 20 years? This direction gives full control of a silicon roadmap. They can make it whatever they want or need. My guess is they have a more specific roadmap than even Intel or AMD at this point, as they're not commodity processors, but now engineered for a very specific purpose.
FullyFunctional 4y ago
I agree, it’s seems unlikely they will have another transition as they now control their own destiny. The fact that Arm64 doesn’t have compressed instructions is obviously a very deliberate choice, thus I can’t agree with the notion that RISC-V compressed instructions could be a potential “advantage” over Arm64. Their absence is a massive advantage in many ways that I have explained over and over on HN and it’s the single biggest stupidity in RISC-V for high-end perf (not microcontrollers).
4y ago

internet_user 4y ago

5 years?