In a shared nothing environment you need 48 different sockets, distinct data structures, and so forth. Given the copy-on-write strategy of many OSes the overhea

In a shared nothing environment you need 48 different sockets, distinct data structures, and so forth. Given the copy-on-write strategy of many OSes the overhead can really be minimal (you'll not get N copies of the executable in memory). The context switching should be more or less the same cost... what I mean is that it's trivial to turn the N proesses design into N independent threads design, as there is no problem with locking, but it is probably not a win.