• @kixik
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    21 year ago

    why developing a x86 compatible arch? Wouldn’t it be better for China to focus on Risc-V? They even had Loongson, but it’s MIPS based…

    Not sure if intel will demand something, or if it actually licensed something (not their business model), so short term might help keeping some x86 SW, but mid term and long term, this doesn’t make much sense, does it?

    • ☆ Yσɠƚԋσʂ ☆OP
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      01 year ago

      Yeah, I was thinking the same. RISC-V seems like the way of the future, and as Apple showed with their new M1 chips, RISC architecture can be much faster and more power efficient than CISC. This was a great article explaining some of the advantages.

      • @kixik
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        1 year ago

        From a technical stand point you’re right, particularly because of limitations imposed on cisc x86 instructions decoding, which given the complexity don’t tolerate as many concurrent decoders as opposed to risc, besides many other advantages of risc. But also, from a technical stand point, take into account that the current intel x86 implementations are really risc ones wrapped around to support cisc. However there are several limitations still, particularly while decoding.

        I believe apple architecture and design decision, go just beyond risc, like sharing the same memory among different processors (cpus, gpus, and so on). That gains M1, M2, and coming SoCs an edge… So it’s not just about risc…

        But my opinion was more about current sanctions, technology banning, and all that sort of artifacts used to restrict and constrain Chinese technology. SoCs are not as short term as one might think, since it’s not cheap investment. So to me, since several years back, they should have focused on risc-v, to avoid such non technical huge problems. They have all resources necessary to pursue a different path, than the more costly and limiting one. Of course changing takes time, but again, they have everything they need to do so. That’s why it was a surprise to see investment on x86 compatible CPUs. But hey, they know their business better than anyone else, :)

        • ☆ Yσɠƚԋσʂ ☆OP
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          11 year ago

          There are two parts to M1/M2 performance. One is the SoC architecture that allows sharing memory without needing a bus. The other is the fact that instructions can be easily processed in batches and then independent instructions in each batch can be computed independently in parallel. The second part is the benefit that all RISC chips share. Being able to scale horizontally by adding more cores is a really nice property.

          With regards to tech sanctions and stuff, I kind of suspect that China just doesn’t care. If US is already set on banning tech exports to China, they have very little leverage to enforce any infringement claims at that point. My guess would be that there are existing applications that still require x86 architecture, and that’s the reason for building such chips domestically.

          It’s worth noting that there are a lot of different companies developing chips in China right now, and it looks like RISC is getting a lot of love there as well. It’s going to be really interesting to see where this all goes in the next decade. We are likely going to start seeing some interesting domestic designs coming out of China in the near future.

          I’m also pretty excited to see if the experiments with other substrates actually end up being put into production at some point. I saw that China is experimenting with carbon based chips and some other alternatives to silicon.

          If one of these approaches can be put into production at scale that could be the equivalent of going from vacuum tubes to transistors. We’re at the point where we’re hitting the limits of what’s possible to do with silicon, but even a crude chip on a different substrate could blow silicon performance away with lots of room for future improvements.