rand.js

// /mnt/sdd/testfile is 4Gb file
// we read this file in 50 "threads"
// node.js results: ~1700 ops/s 7 Mb/s
// randomio results: ~290 ops/s 19 Mb/s

var fs = require("fs"),
    fd = fs.openSync("/mnt/sdd/testfile", "r"),
    i  = 0,
    l  = 1204 * 64;

for (; i < 50; i++) {
    check();
}

function check() {
    var o = Math.random() * 1024 * 3500000,
        b = new Buffer(l);

    console.log("another read");
    fs.read(fd, b, 0, l, o, check);
};