> Almost any code, when micro-optimized, can gain about 10x performance.
well, it depends on where you start from. the speedups can become arbitrarily impressive sounding when the starting point is arbitrarily inefficient.
e.g. if you're starting with a python script that wasn't written with performance in mind and has ended up being compute-bound in pure python number crunching code, if you rewrite the thing in C while thinking a little about appropriate data structures and memory allocation/access -- i.e. replacing a festival of python dict lookups and very frequent memory allocation for tiny intermediate results with indexing into preallocated arrays or so on -- it's quite common to see speedups of 500x - 1000x. this is before micro-optimisation, before introducing SIMD or multi-threading or setting the compiler to build for your exact CPU or so on.
well, it depends on where you start from. the speedups can become arbitrarily impressive sounding when the starting point is arbitrarily inefficient.
e.g. if you're starting with a python script that wasn't written with performance in mind and has ended up being compute-bound in pure python number crunching code, if you rewrite the thing in C while thinking a little about appropriate data structures and memory allocation/access -- i.e. replacing a festival of python dict lookups and very frequent memory allocation for tiny intermediate results with indexing into preallocated arrays or so on -- it's quite common to see speedups of 500x - 1000x. this is before micro-optimisation, before introducing SIMD or multi-threading or setting the compiler to build for your exact CPU or so on.