14 votes

I don't expect to have an ARM-based PC any time soon

Tags: apple, pc, arm, hardware, cpu

16 comments

  1. [7]
    hungariantoast
    Link
    One of the comments on this post is fascinating: I'd love it if someone more knowledgeable could give their thoughts on that comment, specifically the "have tons of Apple proprietary parts and...

    One of the comments on this post is fascinating:

    My big takeaway from the latest release of Apple laptops is that these new laptops aren't necessarily ARM laptops. They are locked down, don't run any operating system other than Big Sur, and have tons of Apple proprietary parts and functions that are not easily portable to any other ARM platform (for example, the security enclave within the M1, the various IO controllers, the neural engines, even the graphics chipset within).

    When a person gets an Apple Silicon Mac, they are not getting an ARM computer. They are getting an Apple computer.

    I'd love it if someone more knowledgeable could give their thoughts on that comment, specifically the "have tons of Apple proprietary parts and functions that are not easily portable to any other ARM platform" part.

    7 votes
    1. tindall
      Link Parent
      I don't have any special knowledge about the M1, but certainly it's very common for, for instance, a program written for an Atmel SAMD chip, which is ARM, to be basically useless on, say, a...

      I don't have any special knowledge about the M1, but certainly it's very common for, for instance, a program written for an Atmel SAMD chip, which is ARM, to be basically useless on, say, a Rockchip ARM applications processor, because the SAMD has different core count, peripherals, etc. This is even true for programs in languages like C, not just assembler, if those programs use the unique peripheral interfaces of a specific chip.

      8 votes
    2. [5]
      NaraVara
      Link Parent
      The M1 Macs are based on a System on a Chip design similar to their phones, tablets, and watches. Where a typical computer is based on a lot of modular, off the shelf parts all slotted into a main...

      The M1 Macs are based on a System on a Chip design similar to their phones, tablets, and watches. Where a typical computer is based on a lot of modular, off the shelf parts all slotted into a main motherboard, an SoC takes all of those parts of a system and puts them on a single chip.

      This has lots of advantages. Everything is very close together and you're dramatically cutting down on connectors that can cause impedance and reduce efficiency. This brings significant gains in energy use, heat generation, and transfer speeds. It also becomes logistically easier as everything is on a single SoC and they can just plug it into whatever form factor they want.

      It also has some disadvantages in terms of modularity, customizability, or upgradability. For Apple's purposes these aren't really issues. Laptops aren't really modular for end users anyway as the parts are generally too small for people to bother fiddling with. We could design them to be more upgradable, but people tend to value size, weight, and battery life more so the tradeoffs aren't worth it.

      There's no reason you couldn't have an ARM PC, though. It's just that Apple's M1 SOC is so good because of all these design considerations that it blows everything else out of the water. You can make other choices and have an ARM chip that talks to a separate GPU and has a separate bank of RAM and whatever else but then it won't be as fast, fanless, or performant as the Macs are. I'm sure one could design one around a different set of tradeoffs though.

      2 votes
      1. [3]
        tindall
        Link Parent
        I don't think this is really what "Jonathan" is talking about. To take the example of a Rockchip applications processor, say the RK3399: it's still a SoC, but it's documented, supported by the...

        I don't think this is really what "Jonathan" is talking about. To take the example of a Rockchip applications processor, say the RK3399: it's still a SoC, but it's documented, supported by the mainline Linux kernel (mostly), and can be purchased and integrated into a third party design. While it has some similar lock-in issues, mostly with the GPU, there are significant efforts to make such things standardized going forward.

        It would be cool to have socketed ARM desktop CPUs with discrete RAM, GPU, etc, but there is a legitimate market to be had in SoC- or SoM-based machines (like the Pinebook/Pinebook Pro!) that are not as deeply proprietary as the M1 Macs nor as modular as an x86 system.

        3 votes
        1. [2]
          NaraVara
          Link Parent
          The challenge there, I think, is that many of the performance bonuses from Apple's solution comes from the architecture of the SoC. You can definitely have an SoC that's set up to be more modular,...

          The challenge there, I think, is that many of the performance bonuses from Apple's solution comes from the architecture of the SoC. You can definitely have an SoC that's set up to be more modular, but you'd be making a different set of trade-offs by doing so that would sacrifice some of the things that make the M1 machines appealing. I think Apple's approach is geared around squeezing as much as they can out of an ARM chip by finding efficiencies literally everywhere else they can. You can lose some of those efficiencies from integration and get a more modular version as well I'm sure.

          I mean, MS did have an ARM based Windows laptop out at one point. It's just nobody wanted it because it was sloooooooow.

          1. tindall
            Link Parent
            I mean, the M1 isn't really less modular than the RK3399 or other SoC applications processors in and of itself - if I could get my hands on some M1s, and on some good documentation, I could...

            I mean, the M1 isn't really less modular than the RK3399 or other SoC applications processors in and of itself - if I could get my hands on some M1s, and on some good documentation, I could probably make a board using it, with some trial and error. It's certainly faster than anything Rockchip makes, but it's also targeting a totally different market. Not documenting it and not selling it to others didn't make it faster.

            4 votes
      2. JXM
        Link Parent
        There are several ARM-based Windows PCs out there (but you can’t buy an ARM Windows license directly). Another major downside to including more and more components inside the SOC is the hit...

        There are several ARM-based Windows PCs out there (but you can’t buy an ARM Windows license directly).

        Another major downside to including more and more components inside the SOC is the hit repairability takes. If your RAM or USB controller dies, you have to replace the entire motherboard. By it’s very nature, an SOC makes things less modular.

        1 vote
  2. Deimos
    Link
    Microsoft recently released a new version of the ARM version of their Surface tablet-laptop hybrid, the "Surface Pro X", which uses their "Microsoft SQ2" chip:...

    Microsoft recently released a new version of the ARM version of their Surface tablet-laptop hybrid, the "Surface Pro X", which uses their "Microsoft SQ2" chip: https://www.youtube.com/watch?v=_QobdWOa02o

    My understanding is that the original Surface Pro X wasn't considered very good, especially because of compatibility issues for a lot of applications, but emulation for 64-bit x86 apps is supposed to be coming soon, and that will probably make a big difference.

    Microsoft does seem to be investing in ARM officially though, so there's definitely some potential from that side. Not many details, but here's an article with a quick comparison between the M1 MacBook Air and the SQ2 Surface Pro X.

    Microsoft's branding approach is so terrible, across all of their products. I just looked at this a couple of weeks ago and it still took me a while to figure out which combination of "Surface", "Go", "Pro", "X", and "Laptop" was the right one for the ARM device. Surface Go Laptop 2? Was that it? Surface Pro Xbox Series X Go?

    5 votes
  3. [7]
    Akir
    Link
    I also don't see ARM replacing x86 en masse any time soon. The only way that might happen is if Apple releases an "open" version of their chips so they can sell to OEMs. ARM is just an instruction...

    I also don't see ARM replacing x86 en masse any time soon. The only way that might happen is if Apple releases an "open" version of their chips so they can sell to OEMs.

    ARM is just an instruction set; the implementation is what matters. And clearly nobody else has been able to get the performance that Apple has. The only ARM vendor that is anywhere close to what Apple has is Qualcomm, and they have exited the server market because they simply were not competitive enough.

    4 votes
    1. [6]
      tindall
      Link Parent
      Well, no, there are ARM server chips that far surpass the performance of the M1. It's just that nobody is targeting the high-end, or even mid-range, laptop market except Apple, because there's no...

      ARM is just an instruction set; the implementation is what matters. And clearly nobody else has been able to get the performance that Apple has.

      Well, no, there are ARM server chips that far surpass the performance of the M1. It's just that nobody is targeting the high-end, or even mid-range, laptop market except Apple, because there's no demand. Apple can manufacture demand because they have monopoly power over devices running Mac OS.

      5 votes
      1. [5]
        Akir
        Link Parent
        That doesn't make much sense to me. Microsoft has spent Billions trying to get ARM on laptops and by most accounts performance was pretty terrible even with native software, and they are still...

        That doesn't make much sense to me. Microsoft has spent Billions trying to get ARM on laptops and by most accounts performance was pretty terrible even with native software, and they are still trying to get it right today. And if there were competitors who could match what Apple is doing, why have they not tried to release a smartphone SoC and beat the competition for performance?

        1. [4]
          tindall
          Link Parent
          Yeah, I mean, no question that Apple made a good processor, and that Microsoft royally fucked up their attempt at making a custom ARM processor. I just don't think that Apple has really made any...

          Yeah, I mean, no question that Apple made a good processor, and that Microsoft royally fucked up their attempt at making a custom ARM processor. I just don't think that Apple has really made any fundamental breakthroughs here. They're flexing their vertical integration, which works well for them.

          1 vote
          1. [3]
            JXM
            Link Parent
            Has Microsoft made their own custom ARM processor? My understanding is that the chips inside their Surface Pro X (the only ARM based computer they sell) are just Qualcomm chips with a custom...

            Has Microsoft made their own custom ARM processor?

            My understanding is that the chips inside their Surface Pro X (the only ARM based computer they sell) are just Qualcomm chips with a custom branding and the original Surface RT just ran an Nvidia Tegra chip.

            EDIT: According to this Wikipedia article the SQ1 and SQ2 used in the Surface Pro X are just slightly faster variants of the Qualcomm 8cx processor.

            4 votes
            1. [2]
              tindall
              Link Parent
              Ah, fair enough. I don't use anything Microsoft sells, so I was just going off the news coverage I saw at the time.

              Ah, fair enough. I don't use anything Microsoft sells, so I was just going off the news coverage I saw at the time.

              2 votes
              1. JXM
                Link Parent
                Same here. I just vaguely remembered reading that when the original Surface Pro X came out (I don't follow Microsoft stuff closely either).

                Same here. I just vaguely remembered reading that when the original Surface Pro X came out (I don't follow Microsoft stuff closely either).

                1 vote
  4. tindall
    Link
    This is a perspective on the recent Apple news I found quite interesting. I don't necessarily agree - I have two ARM "PCs", in the form of the Pinebook and Pinebook Pro, which came out years...

    This is a perspective on the recent Apple news I found quite interesting. I don't necessarily agree - I have two ARM "PCs", in the form of the Pinebook and Pinebook Pro, which came out years before the M1 and which I quite like - but it's certainly an interesting perspective.

    3 votes