• vrighter@discuss.tchncs.de
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    1 year ago

    slight correction. vector processing is available on almost no common architectures. What most architectures have is SIMD instructions. Which means that code that was written for sse2 cannot and will not ever make use of the wider AVX-512 registers.

    The risc-v isa is going towards the vector processing route. The same code works on machines with wide vector registers, or ones with no real parallel ability, but will simply loop in hardware.

    Simd code running on a newer cpu with better simd capabilities will not run any faster. Unmodified vector code on a better vector processor, will run faster

    • mindbleach@lemmy.world
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      1 year ago

      Fancier tech co-opting an existing term doesn’t make the original use wrong.

      Any parallel array operation in hardware is vector processing.

      • vrighter@discuss.tchncs.de
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        1 year ago

        fancy, vector processing predated simd. It’s how cray supercomputers worked in the 90s. You’re the one co opting an existing term :)

        And it is in fact a big deal, with several advantages and disadvantages to both.

          • vrighter@discuss.tchncs.de
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            1 year ago

            from the very first paragraph in the page:

            a vector processor or array processor is a central processing unit (CPU) that implements an instruction set where its instructions are designed to operate efficiently and effectively on large one-dimensional arrays of data called vectors. This is in contrast to scalar processors, whose instructions operate on single data items only, and in contrast to some of those same scalar processors having additional single instruction, multiple data (SIMD) or SWAR Arithmetic Units.

            Where it pretty much states that scalar processors with simd instructions are not vector processors. Vector processors work on large 1 dimensional arrays. Call me crazy, but I wouldn’t call a register with 16 32-bit values a “large” vector.

            It also states they started in the 70s. That checks out. Which dates were you referring to?

            • mindbleach@lemmy.world
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              1 year ago

              This is rapidly going to stop being a polite interaction if you can’t remember your own claims.

              SIMD predates the term vector processing, and was in print by 1966.

              Vector processing is at least as old as the Cray-1, in 1975. It was already automatically parallelizing what would’ve been loops on prior hardware.

              Hair-splitting about whether a processor can use vector processing or exclusively uses vector processing is a distinction that did not exist at the time and does not matter today. What the overwhelming majority of uses refer to is basically just SIMD extensions. Good luck separating the two when SIMT is a thing.

              • vrighter@discuss.tchncs.de
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                1 year ago

                I’m not hair splitting over whether they can or not. scalar processors with simd cannot do vector processing, because vector processing is not simd.

                yes an array of values can be called a vector in a lot of contexts. I could also say that vector processing involves dynamically allocated arrays, since that’s what c++ calls them. A word can be used in mulmiple contexts. When the word vector is used in the term “vector processor” it specifically excludes scalar processors with simd instructions. It refers to a particular architecture of machine. Just being able to handle a sequence of numbers is not enough. Simd can do it, as can scalar processors (one at a time, but they still handle “an array of numbers”). You can’t even say that they necessarily have to execute more than one at a time. A superscalar processor without simd can do that as well.

                A vector processor is a processor specifically designed to handle large lists. And yes, I do consider gpus to be vector processors (exact same shader running on better vector hardware, does run faster.) They are specifically designed for it. simd on a scalar processor is just… not

                • mindbleach@lemmy.world
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                  1 year ago

                  A word can be used in mulmiple contexts.

                  Says user insisting an umbrella term has one narrow meaning.

                  A meaning that would include the SoundBlaster 32.