Why should I use Restify?

I had the requirement to build up a REST API in node.js and was looking for a more light-weight framework than express.js which probably avoids the unwanted features and would act like a custom-built framework for building REST APIs. Restify from its intro is recommended for the same case.

Reading Why use restify and not express? seemed like restify is a good choice.

But the surprise came when I tried out both with a load.

I made a sample REST API on Restify and flooded it with 1000 requests per second. Surprise to me the route started not responding after a while. The same app built on express.js handled all.

I am currently applying the load to API via

var FnPush = setInterval(function() {               for(i=0;i<1000;i++)         SendMsg(makeMsg(i));                }, 1000);function SendMsg(msg) {    var post_data = querystring.stringify(msg);    var post_options = {        host: target.host,        port: target.port,        path: target.path,        agent: false,        method: 'POST',        headers: {'Content-Type': 'application/x-www-form-urlencoded','Content-Length': post_data.length,"connection": "close"            }    };    var post_req = http.request(post_options, function(res) {});    post_req.write(post_data);      post_req.on('error', function(e) {              });     post_req.end();}

Does the results I have got seem sensible? And if so is express more efficient than restify in this scenario? Or is there any error in the way I tested them out?

updated in response to comments

behavior of restify

1. when fed with a load of more than 1000 req.s it stopped processing in just 1 sec receiving till 1015 req.s and then doing nothing. ie. the counter i implemented for counting incoming requests stopped increment after 1015.

2. when fed with a load of even 100 reqs. per second it received till 1015 and gone non responsive after that.