Object.defineProperty vs __defineGetter__ vs normal

Testing in Chrome 31.0.1650.63 32-bit on Windows Server 2008 R2 / 7 64-bit

Test		Ops/sec
Object.defineProperty	for (var i = 0; i < 1000; i++) { obj = {}; Object.defineProperty(obj, "x", {  get: funct['get'],  set: funct['set'] })  obj.x = i;  acc += obj.x; }	ready
__defineGetter__	for (var i = 0; i < 1000; i++) { obj = {}; obj.__defineGetter__('x', funct['get']); obj.__defineSetter__('x', funct['set']);  obj.x = i;  acc += obj.x; }	ready
Normal	for (var i = 0; i < 1000; i++) { obj = {};  obj._x = i;  acc += obj._x; }	ready
Prototype	for (var i = 0; i < 1000; i++) { obj = {}; obj.prototype = {  get x() {   return this._x;  }, set x(value) {   this_x = value;  } }  obj.x = i;  acc += obj.x; }	ready
Setter	for (var i = 0; i < 1000; i++) { obj = {}; obj.setX = function(value) {  this._x = value; }  obj.setX(i);  acc += obj._x; }	ready
defineProperty with local funcs	for (var i = 0; i < 1000; i++) { obj = {}; Object.defineProperty(obj, "x", {  get: function() { return this._x; },  set: function(v) { this._x = v; },  configurable: true })  obj.x = i;  acc += obj.x; }	ready

http://jsperf.com/object-defineproperty-vs-definegetter-vs-normal/49