A single threaded SIMD loop over densely packed data, will outperform the same transformation on a linked list running on 50 threads (this obviously an over generalization and there are transformations and data layouts where this doesn’t hold, but it’s very common. You could also construct cache line aware hybrid data structures, but there are trade-offs).
The only reason you’d need to deal with increasing parallelism (beyond SIMD) is if you wanted it even faster than that.
I’m not saying immutable data isn’t a good idea in many cases (my primary day job language these days is Elixir). What I am saying is that if you are “optimizing for raw speed” immutable data structures are almost never the right choice.
That doesn’t mean immutable data structures can’t be fast enough to be the best choice in many situations.
The only reason you’d need to deal with increasing parallelism (beyond SIMD) is if you wanted it even faster than that.
I’m not saying immutable data isn’t a good idea in many cases (my primary day job language these days is Elixir). What I am saying is that if you are “optimizing for raw speed” immutable data structures are almost never the right choice.
That doesn’t mean immutable data structures can’t be fast enough to be the best choice in many situations.