Note that SIMD on CPUs is somewhat different to GPU style "SIMD" (particularly for cases where you want fixed width SIMD vs arbitrary vector processing (ala SPM

Note that SIMD on CPUs is somewhat different to GPU style "SIMD" (particularly for cases where you want fixed width SIMD vs arbitrary vector processing (ala SPMD, ISPC, CUDA etc)). JSON parsing, for example, doesn't scale in the same way as typical graphics applications do with wide vectors, for example. It's just that the traditional model of byte-by-byte parsing is very inefficient - SIMD implementations just exploit some of the unused parallelism available in CPUs. It's still very much a latency bound problem, and has complex control flow problems, which is why it wouldn't run well on a GPU, yet runs well on CPU SIMD.