Network Services Architecture Question.

My question is hypothetical: Your writing a multi-client service application, what architecture for the sockets would you choose (and why)?

A Blocking approach where each socket is accepted and has its own thread,

OR

A nonblocking approach using far fewer threads with a select loop.

Im curious to know which performs better under which situations and why you would choose one over another.

I had always heard that the blocking/threading approach is easier, but the async/select method yields higher performance. Not sure how much higher. I've always used the approach with threads.