stream_socket_pair

Are sockets created via stream_socket_pair more efficient for IPC than standard socket/port communications? I want to open a process with proc_open, and I want to use a socket to for IPC. One solution is to just create a socket in the parent and pass the port number to the child. Then, when the child starts, it would connect to the local port via a socket. Would it be better to use "stream_socket_pair" to create a pair of IPC socets and then somehow pass the socket descriptor via the proc_open call? Does anyone have any experience passing a socket handle via the descriptor array in proc_open? Thanks, Bob