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The Forgetful CPU (Linux on M4)

267 points · 203 comments · signa11

  1. sscaryterry · · focus · HN ↗
    Imagine how big Apple would/could be if they embraced open hardware. They do have a moat here. macOS is so bloated, I hate it, but the hardware is just so much better than anything else.
    1. MBCook · · focus · HN ↗
      Apple is a vertical company. They don’t WANT to sell you hardware. They don’t want to sell you software.

      They only want to sell the whole package. You might as well ask the Catholic Church to start a rap music 8-track only record club. Same probability.

      The hardware is a means to an end, and nothing else to them.

      1. UltraSane · · focus · HN ↗
        But Apple could make a lot of money selling Linux servers with their CPUs.
        1. internet2000 · · focus · HN ↗
          Why would they want to? They make even more money selling their own computers with their CPUs.
          1. UltraSane · · focus · HN ↗
            The Server market is enormous with a much higher average selling price. It would make perfect sense for Apple to make servers if it meant more revenue and profit than they could make not doing it. There are rumors that Apple is planning a M8 based server in 2029.
            1. fragmede · · focus · HN ↗
              That's a helluva rumor. Apple tried b2b with Xserve, back in the day, but didn't have the stomach for it.
              1. boredatoms · · focus · HN ↗
                That’s because they tried integration with the rest of their SW ecosystem.

                If they just did motherboards with cpu/ram/pcie and let other OEMs build complete systems the story would be very different

                1. scheme271 · · focus · HN ↗
                  They tried it with various open systems that allowed licensed powerpc clones of their systems and they ended it because it reduced their profits as people bought the clones instead of mac hardware. I don't see them redoing that anytime soon.
                  1. MBCook · · focus · HN ↗
                    Also in that case they didn’t even own the hardware. They were IBM chips. They just had a reference design and a BIOS.
                2. MBCook · · focus · HN ↗
                  That still doesn’t overcome the issue that they are selling every single one they can already. They have no need for additional chip sales.

                  All the capacity at all the fabs is booked up for years. They can’t make more if they want to.

                  So any hypothetical sales of OEM style guts would only cut into the number of Macs they can sell to existing customers. And there’s no way they would ever do that.

                  1. adgjlsfhk1 · · focus · HN ↗
                    > They have no need for additional chip sales.

                    Higher margins?

                    1. SXX · · focus · HN ↗
                      Servers need a lot of RAM. Apple can either make 42 iPhones with 12GB or one server with 512GB RAM.

                      42 people with iPhone will buy airpods, some subscriptions and apps. They also be vendor locked into Apple ecosystem and almost guaranteed to bring more iPhone sale in 3 years.

                      Apple must be dumb to canibalize their own market.

              2. Wowfunhappy · · focus · HN ↗
                With the Xserve, all Apple had to sell was repackaged Intel systems—with an Apple markup. They had nothing special to offer on the hardware side.

                Now they have Apple Silicon.

                1. pjmlp · · focus · HN ↗
                  It really isn't that great when comparing against server systems.

                  I think most people here never seen the inside of sliding pizza boxes on server racks, really seeing them.

            2. toast0 · · focus · HN ↗
              If Apple cared about the server market, they would have added syncookies into their TCP stack. Seems like they should have done it during the time of Xserve... it would have been somewhat straightforward to pull it in from upstream BSD back then. But they still haven't (last I checked).

              Apple doesn't have the business to business support organization to make this kind of thing work either.

              1. Asmod4n · · focus · HN ↗
                Apple also has no api to write a fast server.

                Libdispatch is a burden to use for a server because of its book keeping overhead, and their history with kqueue makes it hard to convince someone to use it.

                1. Pesthuf · · focus · HN ↗
                  Isn’t kqueue pretty much as fast as epoll?

                  There’s no io_uring, but in practice, almost all servers run epoll anyway, don’t they?

                  1. dijit · · focus · HN ↗
                    epoll isn’t very fast, kqueue is indeed much faster as a primitive.

                    MacOS’s implementation is an order of magnitude or more slower than (say) FreeBSD though, so its not a valid comparison that the syscall simply exists.

                    Another example of a syscall performing differently would be gettimeofday() in OpenBSD vs linux, its an extremely cheap operation in Linux but quite costly in OpenBSD despite being identical at the kernel boundary.

                  2. Asmod4n · · focus · HN ↗
                    epoll is kinda slow compared to io_uring, I am typically getting double the perf just switching to uring.
              2. UltraSane · · focus · HN ↗
                If Apple can create one of the best CPUs in the world they can create and support a server that uses it.
                1. toast0 · · focus · HN ↗
                  Sure, they can, but they've done servers several times in their past and I think it's reasonable to guess that results will be similar. Sure, they have a very nice CPU, but they don't have a good reputation for enterprise support and that's more important to selling servers than having the best cpus. If their cpus were 10x as good as the competition, maybe, but they're not, especially in a server context where power and cooling are abundant.
            3. podocarp · · focus · HN ↗
              Lol they don't even have tun tap in the kernel, can't even host VMs properly without extra setup or hacks
            4. alsetmusic · · focus · HN ↗
              The rumors are that it’s for internal use. It’s already known that they have custom M2 or M3 servers that they don’t sell to the public. Source: multiple episodes of the Accidental Tech Podcast that discuss articles about this.
              1. MBCook · · focus · HN ↗
                And it makes a ton of sense in that context. I don’t think it makes any sense as a commercial product.

                A mega-AI workstation could.

                But server? Nah.

            5. mbreese · · focus · HN ↗
              Apple tried to address the server market 20 years ago during the PowerPC days (and later Intel). Their Xserves were really well designed machines and worked well. And yes, they also ran Linux (Yellowdog, IIRC).

              It failed.

              But I think that they learned something really valuable. As a company, they don’t have a good understanding the server market or how to sell to it. Their premium product style just didn’t have a place in the race to the bottom server market.

              We had two in my grad school lab that we used as web servers. But that was the problem - it was a premium designed product that wasn’t any better of a web server than a plain (cheaper) Dell 1U box.

              Maybe things would be different now that they have a really unique chip. ARM as a whole ecosystem has more buy-in from other companies than PowerPC did. Their performance per watt and GPU design might make more of a difference this time around.

              But I can’t see Apple being able to release and sell a data center centric server. I think others might have a better chance.

              1. UltraSane · · focus · HN ↗
                The extremely important difference is that now Apple has some of the best CPUs in the world.
                1. SXX · · focus · HN ↗
                  Apple CPUs are good except most of server workloads benefit more from 128+ core monsters and not just fewer better cores.

                  MacOS is not a server OS either and actually maturing M* support in Linux will take years. And for inference Nvidia is years ahead of Apple.

                  So best Apple can hope for is some niche market.

                  1. t-3 · · focus · HN ↗
                    A lot of Apple's advantages come from tightly-linked memory and compute in a fully integrated design. I somewhat doubt that advantage can fully translate to servers, where features like hot-swappable memory are standard. Maybe they should skip mid-scale and head straight to mainframes?
                    1. wtallis · · focus · HN ↗
                      Hot-swappable memory is probably much more common in mainframes than mainstream servers. A typical x86 server still requires you to power it off before replacing DIMMs. Meanwhile, NVIDIA and AMD have both recently done some rather Apple-like server processors that solder CPU, GPU, and RAM to the same package/module.
                2. [deleted] · · focus · HN ↗

                  [deleted]

            6. AnthonyMouse · · focus · HN ↗
              > There are rumors that Apple is planning a M8 based server in 2029.

              The issue is that the current Apple way of designing hardware doesn't really work for servers. An individual 1U server can easily cost $50,000 or more. Soldering everything together so that if a single memory chip goes bad you have to replace the entire machine instead of that one stick is going to make customers unhappy. Likewise, they expect to be able to add storage or network ports, and expect the software to have enough openness that the new systems will work with their existing enterprise SAN or what have you.

              Obviously Apple could make open server hardware, but then people might start wondering why they can't make open laptop hardware.

              1. Rohansi · · focus · HN ↗
                They could use sockets for the memory. Easily justifiable because there is much more available space in a server than their other products. Just look at how bare the Apple Silicon Mac Pro mainboard looks.
                1. AnthonyMouse · · focus · HN ↗
                  The problem was never space. They solder the RAM even in the laptops that have 8GB and the same memory bandwidth as ordinary PC laptops with modular RAM, and DIMMs take up less space on the board because the memory chips can then be attached double-sided to a DIMM that only needs as much space on the board as it takes for an edge connector.

                  The primary advantage of soldering compared to DIMMs is that the traces can be slightly shorter without routing them through an edge connector, but if you need that then you can use CAMM.

                  They solder the memory because then you can't upgrade it. Strong evidence for this is that they do the same thing with the SSD, for which there is no even plausible other justification.

                  1. Rohansi · · focus · HN ↗
                    The main reason is definitely just overcharging people for upgrades but size also includes thickness. SOCAMM would add at least the thickness of an extra PCB. I don't really agree with Apple's obsession to make their devices as thin as possible (they're thin enough!) but it would be a valid concern for them.

                    > Strong evidence for this is that they do the same thing with the SSD

                    Worse, they have a proprietary module that they use in the Mac Mini. Couldn't have just used M.2.

            7. internet2000 · · focus · HN ↗
              Higher ASP but even higher COGS.
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