I have several hundred "row" elements like this:

```
<div class='row'>
  <div class='cell'></div>
  <div class='cell'></div>
  <div class='cell'></div>
</div>

```

I need to get their clientHeight after they have been rendered on the page already. I know that the "clientHeight" property forces a reflow and this kills my performance since there are so many of them. However - they are already rendered and I know that their size doesn't change between the time they are rendered and the time that I query for their height. 

Is there a way to tell the browser to NOT reflow when querying for the height ?
Moreover - the webkit inspector says:

```
Layout tree size  5901
Layout scope      Whole document

```

And the divs are within an absolutely positioned ancestor - shouldn't only the absolutely positioned element be reflowed?

**Edit:**

So the answers provided are correct. I was in fact dirtying the layout because I had this loop:

```
rows.each(function(){
  $(this).css('height', this.clientHeight);
});

```

Changing the code to this fixed the problem:

```
var heights = rows.map(function(){
  return this.clientHeight;
});
rows.each(function(){
  $(this).css('height', heights.shift());
});

```