jQuery fadeIn and fadeOut lag in chrome but not in Firefox

Question

I have an overlay that should appear on top of everything by fading in after the user clicks on a button. I'm using jQuery fadeIn and fadeOut for this. However, there is significant lag in chrome while doing so, while in Firefox the animations run smooth.

Here's my HTML:

<div class="overlay">
    <div class="overlay_profile">
        <div class="overlay_contents">
            <div class="overlay_profile_info">
                <img src="images/avatars/1.gif" />
                <div class="overlay_profile_info_text_username">
                    Qub1
                </div>
                <div class="overlay_profile_info_text_other">
                    Level 1
                </div>
            </div>
        </div>
    </div>
    <div class="overlay_close">X</div>
</div>
<div class="overlay_shadow"></div>

And my CSS:

.overlay {
    display: none;
    padding: 20px;
    position: fixed;
    top: 150px;
    right: 150px;
    bottom: 100px;
    left: 150px;
    z-index: 2;
    background: #978470;
    border: 3px solid #CCC;
    border-radius: 20px;
    box-shadow: 0 0 20px #000, inset 0 0 10px #6A5C4E;
}

.overlay_shadow {
    display: none;
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    z-index: 1;
    background: rgba(0, 0, 0, 0.5);
}

And JavaScript:

$(document).ready(function(){
    $(".menu_arrow").add(".overlay_close").add(".overlay_shadow").click(function() {
        if($(".overlay").is(':visible')) {
            $(".overlay").add(".overlay_shadow").fadeOut("normal");
        } else {
            $(".overlay").add(".overlay_shadow").fadeIn("normal");
        }
    });
});

Does anyone have an idea why chrome would be lagging? Is it the heavy use of CSS3?

Any help is appreciated!

Answer 1

Try adding these rules to your classes:

{
    -webkit-transform: translatez(0);
    -moz-transform: translatez(0);
    -ms-transform: translatez(0);
    -o-transform: translatez(0);
    transform: translatez(0);
}

This forces/tricks Chrome to send the CSS3 operations to the GPU, which should speed it up.

I guess it's just because Chrome is a bit shy about what it transfers to the GPU unlike Firefox.