Test Nodejs read and write file performance

nodejs_perf.js

var fs = require('fs');
var from = new Date().getTime();
for (var i = 1; i <= 10; i++) {
	fs.readFile("test.mp4",function(err, data) {
	    if(err)
	        console.log("read error: ", err);
	    else {
			fs.writeFile(__dirname + "/new.mp4", data , function(err) {
			    if(err) {
			        console.log("write error: ", err);
			    } else {
					console.log("length: ", (new Date().getTime() - from)/1000);			
			    }
			}); 
	    }
	});
};