perf.js

var pre = [0.204,
0.164,
0.020,
0.093,
0.117,
0.124,
0.076,
0.106,
0.117,
0.097,
0.068,
0.076,
0.091,
0.097,
0.088,
0.092,
0.083,
0.104,
0.119,
0.066,
0.389,
0.066,
0.073,
0.103,
0.276,
0.125,
0.065,
0.221,
0.083,
0.108,
0.087,
0.118,
0.080];

var post=[0.252,
0.156,
0.247,
0.114,
0.334,
0.094,
0.111,
0.089,
0.451,
0.131,
0.089,
0.108,
0.075,
0.068,
0.066,
0.064,
0.065,
0.067,
0.077,
0.064,
0.068,
0.066,
0.070,
0.076,
0.068,
0.081,
0.068,
0.072,
0.067,
0.084,
0.069,
0.071,
0.069];

var post2 = [ 0.376,
0.163,
0.118,
0.105,
0.000,
0.060,
0.056,
0.062,
0.097,
0.184,
0.100,
0.061,
0.059,
0.135,
0.054,
0.054,
0.050,
0.059,
0.143,
0.062,
0.053,
0.076,
0.147,
0.094,
0.042,
0.190,
0.058,
0.066,
0.055,
0.065,
0.035,
0.087,
0.096];

var productItemRenderPre = [1.040,
1.217,
1.214,
1.020,
0.801,
1.517,
0.582,
1.263,
0.899,
0.683,
0.675,
0.542,
0.603,
1.155,
0.931,
0.729,
0.701,
0.672,
0.562,
0.567,
0.608,
1.597,
0.586,
0.840,
1.136,
1.039,
0.995,
0.721,
0.835,
0.540,
0.711,
1.266,
0.793];

var productItemRenderPost = [1.095,
0.635,
0.490,
0.147,
0.427,
0.529,
0.747,
2.017,
0.553,
1.397,
0.656,
0.915,
0.745,
0.758,
0.699,
0.754,
0.825,
0.507,
0.529,
0.455,
1.356,
0.703,
0.544,
0.476,
0.197,
0.618,
0.450,
0.741,
0.719,
0.698,
0.640,
0.580,
1.286];

var productItemRenderPost2 = [0.746,
0.534,
0.565,
0.419,
0.292,
0.319,
0.268,
0.455,
0.509,
0.426,
0.515,
0.482,
1.790,
0.279,
0.257,
0.298,
0.433,
0.426,
0.557,
0.371,
0.271,
0.284,
0.332,
0.316,
0.316,
1.744,
0.466,
0.684,
0.577,
0.594,
0.459,
0.106,
0.551];

var productItemRenderPost3 = [ 0.535,
 0.537,
 0.398,
 0.439,
 0.455,
 0.636,
 0.433,
 0.409,
 0.401,
 0.630,
 0.685,
 1.110,
 1.232,
 0.889,
 2.237,
 0.976,
 0.491,
 0.408,
 0.725,
 0.589,
 0.409,
 0.430,
 0.764,
 0.424,
 0.645,
 1.421,
 0.590,
 0.656,
 0.420,
 0.632,
 0.406,
 0.779,
 0.269];

var productItemRenderPost4 = [ 0.619,
 0.532,
 0.189,
 1.324,
 0.314,
 0.299,
 0.420,
 0.450,
 0.411,
 2.347,
 0.998,
 0.339,
 0.377,
 0.061,
 0.180,
 0.423,
 0.265,
 0.316,
 0.322,
 0.319,
 0.330,
 0.001,
 0.293,
 0.402,
 0.298,
 0.416,
 0.746,
 0.265,
 0.247,
 0.320,
 0.316,
 0.496,
 0.546];

var productItemRenderPost5 = [1.059,
0.487,
0.459,
0.985,
0.889,
1.080,
0.583,
0.428,
0.658,
0.739,
0.499,
0.978,
0.547,
0.508,
0.405,
0.444,
0.452,
0.440,
0.554,
1.477,
0.397,
0.355,
0.413,
0.715,
0.639,
0.924,
0.508,
0.422,
0.611,
0.689,
0.521,
0.608,
0.359
     ];

var productItemRenderPost6 = [1.060,
0.496,
0.831,
0.417,
0.397,
0.437,
0.535,
0.673,
0.497,
0.827,
1.235,
0.506,
0.473,
0.568,
0.783,
0.406,
0.618,
0.648,
0.388,
0.486,
0.400,
0.365,
0.428,
0.831,
0.501,
0.274,
0.332,
0.431,
0.615,
0.706,
0.434,
0.534]

var productItemRenderPost7 = [0.848,
0.911,
0.492,
0.500,
0.405,
0.551,
0.368,
0.979,
0.870,
0.549,
0.621,
0.612,
0.383,
0.385,
0.446,
0.524,
0.419,
0.543,
0.339,
0.374,
0.282,
0.892,
0.393,
0.374,
0.571,
1.050,
0.396,
0.655,
0.323,
0.666,
0.740,
0.574,
0.364];


function getAverage(array) {
	var sum = 0;
    
	for( var i = 0; i < array.length; i++ ){
   		sum += array[i]; //don't forget to add the base
	}

	return sum/array.length;
}

$('body')
    .append('<p>product-item.render() Pre:: ' + getAverage(productItemRenderPre) + 'ms</p>')
	.append('<p>product-item.render() Post:: ' + getAverage(productItemRenderPost) + 'ms</p>')
    .append('<p>product-item.render() Post:: ' + getAverage(productItemRenderPost2) + 'ms</p>')
	.append('<p>product-item.render() Post:: ' + getAverage(productItemRenderPost3) + 'ms</p>')
	.append('<p>product-item.render() Post:: ' + getAverage(productItemRenderPost4) + 'ms</p>')
    .append('<p>product-item.render() Post:: ' + getAverage(productItemRenderPost5) + 'ms</p>')
	.append('<p>product-item.render() Post:: ' + getAverage(productItemRenderPost6) + 'ms</p>')
	.append('<p>product-item.render() Post:: ' + getAverage(productItemRenderPost7) + 'ms</p>')
;

console.log (getAverage(pre));
console.log (getAverage(post));
console.log (getAverage(post2));