as3 array vector splice test

import flash.events.Event;
import flash.utils.getTimer;
import flash.display.Sprite;

var av:Vector.<Sprite> = new <Sprite>[this, this, this,this];
var bv:Vector.<Sprite> = new <Sprite>[];

var aa:Array = [this, this, this,this];
var ba:Array = [];

for (var i=0; i < 1E7; i++) {
    ba.push(this);
    bv.push(this);
}

var index:int = 2;

super.addEventListener(Event.ENTER_FRAME, test);

function test(e:Event):void {
    var t1:int = getTimer();
    aa.splice(index, 2, aa[index + 1], aa[index]);
    var t2:int = getTimer();
    ba.splice(index, 2, ba[index + 1], ba[index]);
    trace(t2-t1, getTimer()-t2);

    t1 = getTimer();
    av.splice(index, 2, av[index + 1], av[index]);
    t2 = getTimer();
    bv.splice(index, 2, bv[index + 1], bv[index]);
    trace(t2-t1, getTimer()-t2);
    trace('-');

}

/**
0 6
0 0
-
0 6
0 0
-
0 6
0 0
-
0 7
0 0
-
0 6
0 0
-
0 7
0 0
-
0 7
0 0
-
0 6
0 0
-
*/