Multi-threading?

And here is my final code for my needs, this won't stack overflow:

nqsort: 425.1626749999999788087 (0.343325)

// Non-nested quick sort
Array.prototype.nqsort = function(depth) {
  var pivot, i=0, left, right;
  if (depth === undefined) {
    depth = parseInt(Math.floor(this.length/5), 10);
  }
  var begin = Uint16Array(depth);
  var end = Uint16Array(depth);

  begin[0] = 0;
  end[0] = this.length;

  while (i >= 0) {
    left = begin[i]; right = end[i]-1;
    if (left < right) {
      pivot = this[left];
      if (i === depth-1) return false;
      while (left < right) {
        while (this[right] >= pivot && left < right) right--;
        if (left < right) this[left++] = this[right];
        while (this[left] <= pivot && left < right) left++;
        if (left < right) this[right--] = this[left];
      }
      this[left] = pivot; begin[i+1] = left+1;
      end[i+1] = end[i]; end[i++] = left;
    } else i--;
  }
  return true;
};
Uint16Array.prototype.nqsort = Array.prototype.nqsort;

References: http://alienryderflex.com/quicksort/