• barsoap@lemm.ee
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    5 months ago

    Performance level

    Not good. That bench is from a BananaPi with the same SoC, via reddit (sorry).

    Maybe about an A55. If you want a performant RISC-V you’ve gotta wait until stuff leaks out of the European Supercomputer stuff onto the market though that one probably won’t have good IPC either unless it’s vector, or maybe one of the big chip design companies will grace us with a chip with a RISC-V insn decoder.

    • wewbull
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      5 months ago

      I think those will have to have fairly good IPC, otherwise they won’t be able to keep the array processors fed with work.

      Guess we’ll see.

      • barsoap@lemm.ee
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        5 months ago

        You can keep the array processors fed with low IPC and frequency by having absolutely massive vector lengths, the engineering for that kind of processor isn’t in the pipeline, branch prediction etc. it’s in the APUs and how to stream data into them. Much more like GPUs, in fact RISC-V has instructions for gather/scatter.

        • wewbull
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          5 months ago

          Disagree. You quite often have a fair degree of scaler code in between portions which are embarrassingly parallel. If you don’t have a decent scaler core you are destined to be become bottlenecked on them. It’s not that different to a CPU / GPU pairing. If one is under powered, it determines the speed of the overall system.

          If you look at what a company like Tenstorrent is doing, they are designing high performance Risc-V cores as a side aspect of their main goal of doing array processors. The reason is because they couldn’t find scaler cores on the market with enough performance to not bottleneck the system.