So I have some cool Image Processing algorithm. I have written it in OCaml. It performs well. I now I can compile it as C code with such command ocamlc -output-obj -o foo.c foo.ml (I have a situation where I am not alowed to use OCaml compiler to bild my programm for my arcetecture, I can use only specialy modified gcc. so I will compile that programm with sometyhing like gcc -L/usr/lib/ocaml foo.c -lcamlrun -lm -lncurses and Itll run on my archetecture.)
I want to know in general case can a program written in C be faster than one written in OCaml and translated to C?
Yes. But all generalisations about such matters are just that, generalisations, and you (and others here) will be able to find counter-examples.
Of course this answer is, itself, a generalisation.