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AMD holds an arm license and uses them as part of the software tpu in the pro series processors as I understand. It's not unreasonable to assume they could make

AMD holds an arm license and uses them as part of the software tpu in the pro series processors as I understand. It's not unreasonable to assume they could make some ARM x86 hybrid CPU (like apple did for Rosetta) or a mixed arch chip we've never seen before that can run emulators native. Who knows.

AnthonyMouse 3y ago
But what would be the point of that? If you're already buying it from AMD and the previous generation was x86 so that's what gives backwards compatibility, just do another x86 one. The reason to switch to ARM is to get it from someone other than Intel or AMD.
- lmm 3y ago
  The reason to switch to ARM is to get better performance, especially per-watt. If the supplier that's making your graphics card can deliver that, then why risk onboarding someone new?
  - jwells89 3y ago
    In addition to better perf per watt, it’d allow them to shrink the console, potentially to something as small as a Mac Mini or NUC. Less need for cooling means a smaller console. This could help them make inroads to people who might not have considered a home console before due to their relatively large size. Wouldn’t be surprised if the Switch did well with this market and now MS wants a slice of that pie.
  - isthatafact 3y ago
    > The reason to switch to ARM is to get better performance, especially per-watt. I am not expert, but I cannot remember ever hearing that before. Why would arm have better absolute performance than x86? As a spectator, reading tech press about architectures gave me the impression that even in performance per watt, the advantage arm has over x86 is fairly small, just that arm chip makers have always focused on optimizing for low power performance for phones.
    - lmm 3y ago
      > I am not expert, but I cannot remember ever hearing that before. Why would arm have better absolute performance than x86? Better general design, or easier to include more cache. All the normal reasons one architecture might perform better than another. I mean, you heard about Apple switching all their processors to ARM, right? > As a spectator, reading tech press about architectures gave me the impression that even in performance per watt, the advantage arm has over x86 is fairly small, just that arm chip makers have always focused on optimizing for low power performance for phones. Intel would certainly like you to believe that. But for all their talk of good low-power x86s being possible, no-one's ever actually managed to make one.
      - scheeseman486 3y ago
        There's an anecdote from Jim Keller that Zen is so modular that it'd be possible to swap out the x86 instruction decode block with an ARM one with relatively little effort. He's also been saying for a while now that ISA has little bearing on performance and efficiency anymore. Apple's decision to switch to ARM had many reasons, licensing being just as important as performance, perhaps more so. The low power variants of Zen are very efficient. You're still looking at Intel, but they've been leapfrogged by AMD on most fronts over the past half decade (still not market share, but Intel still has their fabrication advantage).
        lmm 3y ago
        I'll believe that when I see a Zen-based phone with a non-awful battery life. Yes AMD are ahead of Intel in some areas, but they've got the same vested interest in talking up how power-efficient their x86 cores can be that may not actually be based in reality.
        scheeseman486 3y ago
        You won't see that happen because AMD have no interest in targeting phones. Why bother? Margins are thin, one of x86's biggest advantages is binary backwards compatibility but that's mostly meaningless on Android, there's additional IP and regulatory pain points like integration of cellular modems. Intel tried and ran into most of those same problems. Their Atom-based SoCs were pretty competitive with ARM chips of the day, it was the reliance on an external modem, friction with x86 on Android and a brutally competitive landscape that resulted in their failure. Regardless of architectural advantages from one vendor or another, the point remains that the arguable preeminent expert in CPU architecture believes that ISA makes little difference and given their employment history it's hard to make the argument of bias.
mratsim 3y ago
The stuff on the PRO is a Xilinx FPGA, or they have both an ARM Processor and an FPGA?
- deleted 3y ago
  [deleted]
- p_l 3y ago
  The NPUs are effectively hard IP blocks on xilinx FPGA fabric (i.e. there are close to no LUTs there - the chip takes in Xilinx bitstream but the only available resources are hard IP blocks) There's also Xtensa cores (audio coprocessor) and ARM cores included (PSP, Pluton, and I think there's extra ARM coprocessor for handling some sensor stuff optionally)
bradfa 3y ago
AMD has previously made a variety of ARM CPUs, such as the recent Opteron “Seattle” parts. https://en.wikichip.org/wiki/amd/cores/seattle https://en.wikichip.org/wiki/amd/cores/seattle
_kbh_ 3y ago
> AMD holds an arm license and uses them as part of the software tpu in the pro series processors as I understand. AMD uses ARM for its PSP as well which is more than just a TPM. But afaik it also matters what type of license AMD has. AMD would be need an ARM architecture license (like Apple has). This license allows you to do whatever you want with the chip (such as adding a x86 style memory model). The downside to the architecture license is you have clean room design the chip entirely.
mkopec 3y ago
All Zen 1 CPUs and newer have the PSP / ASP security processor which is ARM based and runs before the x86 cores are released from reset. This applies to all Zen models, not just the PRO versions. The fTPM does indeed run on the PSP, so on the ARM cores, among many other things like DRAM training.

AnthonyMouse 3y ago

But what would be the point of that? If you're already buying it from AMD and the previous generation was x86 so that's what gives backwards compatibility, just do another x86 one. The reason to switch to ARM is to get it from someone other than Intel or AMD.

lmm 3y ago
The reason to switch to ARM is to get better performance, especially per-watt. If the supplier that's making your graphics card can deliver that, then why risk onboarding someone new?
- jwells89 3y ago
  In addition to better perf per watt, it’d allow them to shrink the console, potentially to something as small as a Mac Mini or NUC. Less need for cooling means a smaller console. This could help them make inroads to people who might not have considered a home console before due to their relatively large size. Wouldn’t be surprised if the Switch did well with this market and now MS wants a slice of that pie.
- isthatafact 3y ago
  > The reason to switch to ARM is to get better performance, especially per-watt. I am not expert, but I cannot remember ever hearing that before. Why would arm have better absolute performance than x86? As a spectator, reading tech press about architectures gave me the impression that even in performance per watt, the advantage arm has over x86 is fairly small, just that arm chip makers have always focused on optimizing for low power performance for phones.
  - lmm 3y ago
    > I am not expert, but I cannot remember ever hearing that before. Why would arm have better absolute performance than x86? Better general design, or easier to include more cache. All the normal reasons one architecture might perform better than another. I mean, you heard about Apple switching all their processors to ARM, right? > As a spectator, reading tech press about architectures gave me the impression that even in performance per watt, the advantage arm has over x86 is fairly small, just that arm chip makers have always focused on optimizing for low power performance for phones. Intel would certainly like you to believe that. But for all their talk of good low-power x86s being possible, no-one's ever actually managed to make one.
    - scheeseman486 3y ago
      There's an anecdote from Jim Keller that Zen is so modular that it'd be possible to swap out the x86 instruction decode block with an ARM one with relatively little effort. He's also been saying for a while now that ISA has little bearing on performance and efficiency anymore. Apple's decision to switch to ARM had many reasons, licensing being just as important as performance, perhaps more so. The low power variants of Zen are very efficient. You're still looking at Intel, but they've been leapfrogged by AMD on most fronts over the past half decade (still not market share, but Intel still has their fabrication advantage).
      - lmm 3y ago
        I'll believe that when I see a Zen-based phone with a non-awful battery life. Yes AMD are ahead of Intel in some areas, but they've got the same vested interest in talking up how power-efficient their x86 cores can be that may not actually be based in reality.
        scheeseman486 3y ago
        You won't see that happen because AMD have no interest in targeting phones. Why bother? Margins are thin, one of x86's biggest advantages is binary backwards compatibility but that's mostly meaningless on Android, there's additional IP and regulatory pain points like integration of cellular modems. Intel tried and ran into most of those same problems. Their Atom-based SoCs were pretty competitive with ARM chips of the day, it was the reliance on an external modem, friction with x86 on Android and a brutally competitive landscape that resulted in their failure. Regardless of architectural advantages from one vendor or another, the point remains that the arguable preeminent expert in CPU architecture believes that ISA makes little difference and given their employment history it's hard to make the argument of bias.

mratsim 3y ago

The stuff on the PRO is a Xilinx FPGA, or they have both an ARM Processor and an FPGA?

deleted 3y ago
[deleted]
p_l 3y ago
The NPUs are effectively hard IP blocks on xilinx FPGA fabric (i.e. there are close to no LUTs there - the chip takes in Xilinx bitstream but the only available resources are hard IP blocks) There's also Xtensa cores (audio coprocessor) and ARM cores included (PSP, Pluton, and I think there's extra ARM coprocessor for handling some sensor stuff optionally)

bradfa 3y ago

AMD has previously made a variety of ARM CPUs, such as the recent Opteron “Seattle” parts. https://en.wikichip.org/wiki/amd/cores/seattle https://en.wikichip.org/wiki/amd/cores/seattle

_kbh_ 3y ago

> AMD holds an arm license and uses them as part of the software tpu in the pro series processors as I understand. AMD uses ARM for its PSP as well which is more than just a TPM. But afaik it also matters what type of license AMD has. AMD would be need an ARM architecture license (like Apple has). This license allows you to do whatever you want with the chip (such as adding a x86 style memory model). The downside to the architecture license is you have clean room design the chip entirely.

mkopec 3y ago

All Zen 1 CPUs and newer have the PSP / ASP security processor which is ARM based and runs before the x86 cores are released from reset. This applies to all Zen models, not just the PRO versions. The fTPM does indeed run on the PSP, so on the ARM cores, among many other things like DRAM training.