A few different ways to make Arrays; which one gets the best performance?

gistfile1.eclass

jsc make-some-arrays.js
test #6:
total time: 0.405 seconds
test #7:
total time: 0.892 seconds

make-some-arrays.js

function makeSomeArrays(){
    var outputter = function(fn){
        var ts = new Date().getTime();
        fn();
        var te = new Date().getTime();
        console.log("total time: " + (te-ts)/1000 +
            " seconds");
    };
 
    // 1 million:
    var L = 1000000;
 
    // use Array constructor; push L new arrays...
    var test1 = function(){
        var a = new Array();
        for (var i=0; i<l ; i++) {
            a.push(new Array());
        }
    };
 
    // same as above - but in each case,
    // declare a length to the array
    var test2 = function(){
        var a = new Array(L);
        for (var i=0; i<L; i++) {
            a.push(new Array(0));
        }
    };
 
    // same as above but via index assignment
    var test3 = function(){
        var a = new Array(L);
        for (var i=0; i<L; i++) {
            a[i] = new Array(0);
        }
    };
 
    // for 4-6: replace Array constructor w/ Array literal
    // notation except where declaring a length
    // (container array, 5 + 6)
    var test4 = function(){
        var a = [];
        for (var i=0; i<L; i++) {
            a.push([]);
        }
    };
 
    var test5 = function(){
        var a = new Array(L);
        for (var i=0; i<L; i++) {
            a.push([]);
        }
    };
 
    var test6 = function(){
        var a = new Array(L);
        for (var i=0; i<L; i++) {
            a[i] = [];
        }
    };
 
    var tests = [test1, test2, test3, test4, test5, test6];
 
    for (var j=0; j<tests.length; j++) {
        console.info("test #" + (j+1) + ":");
        outputter(tests[j]);
    }
}