Most Effective Sockets

Ok, i have heard that there are three ways of using sockets: Asynchronous, Non-Blocking and with Overlapped I/O, and i think that with overlapped i/o we can achieve better performance, but i haven´t found any resource explaining how to use it with sockets, anyone have some? By the way, is there any way of using overlapped i/o in *nix systems?

(Building a cross platform framework for high performance I/O).

Thank you all.

Win32 System Programming by Johnson M. Hart may be a good resource for you. IMHO, I believe he does an excellent job of explaining overlapped I/O and how it pertains to sockets.