> I would like to know if there is something to do to improve colinux
> performance. I mean like using a swap file, or tell colinux how much ram
> there is, or something else.
Buy a faster CPU.
Really. If your program runs to slow and is not swapping there is no other way. Colinux does not introduce overhead for calculations. And only a little for file io. (Hint: more ram means more caching)