• sugar_in_your_tea@sh.itjust.works
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    4 months ago

    The overhead of additional instructions isn’t the issue, they often translate those instructions into a smaller set of actual operations. It’s not like they have a special circuit for every instruction, a lot of instructions translate to a pipeline of multiple, modular circuits.

    The actual silicon will look more like ARM despite having a very large difference in instruction set sizes.

      • sugar_in_your_tea@sh.itjust.works
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        4 months ago

        That depends on what you mean, but here are a few reasonable explanations:

        • Intel’s chips are still on their Intel 7 process (similar to TSMC’s 7nm process), whereas AMD is using TSMC’s 4nm process, so AMD’s CPUs are 2 nodes ahead; smaller process generally means more transistors in the same area, as well as lower power usage per clock
        • AMD’s chiplet architecture makes it easier for them to move the CPU bits to a smaller arch, and the IO bits can stay on a cheaper arch (e.g. AMD uses 4nm for the cores, 6nm for the IO die); this increases yields and dramatically reduces costs, so AMD can invest more in architectural improvements
        • ARM prioritizes battery life over performance, so performance per watt won’t be great at the high end, but it’ll probably win at the low end; they also don’t make their own chips (just designs), so comparing process nodes is meaningless
        • AMD focuses on different aspects of computing than either Intel or ARM, so perhaps they’ve just done a better job optimizing for what you care about

        Anyway, that’s my take.

        • TheGrandNagus@lemmy.world
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          4 months ago

          And for AMD’s 3D v-cache chips, there’s an enormous energy benefit, as taking stuff from the (much larger than usual) cache is far more energy efficient than constantly going back and forwards to RAM.