For the purpose of this question lets say we need to append() 1000 objects to the body element.
You could go about it like this:
I would use native Javascript, normally much faster:
var el = document.getElementById('the_container_id');
var aux;
for(x = 0; x < 1000; x++) {
aux = document.createElement('div');
aux.innerHTML = x;
el.appendChild(aux);
}
EDIT:
There you go a jsfiddle with different options implemented. The @jackwander's solution is, clearly, the most effective one.