High Throughput and bi-direction comm

Greetings,I am trying to get high throughput with bi-directional comm. What I mean is that I have data going from socket-serial and serial-socket. For the socket side I am using select. On the serial side I have tried blocking and non-blocking I/O. The issue is that I do not want to use up all CPU checking the serial port, I also have a web server going and need to check for incoming socket data. Anyone have any suggestions or sample apps. Thanks in advance, David bengaldave@gmail.com