Intresting, but without real test in real server environment with proxy server, db connections, FS usage it hard to tell that it really fast.
i saw many such test where hello world example are blazing fast, but when come to real apps they suck.
And also im not really understand how you got 1m connections when core have only 64k sockets. and there definitelly be a problem with freeing them not only for server but also for test client. There was topic with similar name for erlang long time ago and you can see how they avoid this problem.