简单的jquery幻灯片导致高CPU使用率

<section id="student-blocks">
    <div>
        <h2 class="animated fadeUp">News Item #1</h2>
        <p "animated fadeIn">lorem</p>
    </div>
    <div>
        <h2 class="animated fadeUp">News Item #2</h2>
        <p "animated fadeIn">lorem</p>
    </div>
    <div>
        <h2 class="animated fadeUp">News Item #3</h2>
        <p "animated fadeIn">lorem</p>
    </div>
</section>

$(function ()
{

    $("#student-blocks > div:gt(0)").hide();

    seTinterval(function ()
    {
        $('#student-blocks > div:first')
        .hide()
        .next()
        .fadeIn()
        .end()
        .appendTo('#student-blocks');
    },4000);
});

首先在你的问题上我很怀疑你会通过优化发布的代码得到任何有意义的改进(20％-25％你说的是一个非常高的数字！).但是让我们看看我们能做什么.所以,在你的代码中,你使用区间函数之外的$(‘#student-blocks> div：first’)如：

var el $(‘#student-blocks> div：first’);,并使用el元素变量.
更好的是使用这个选择器：

var el = $("#student-blocks").find("div:first");

此外,根据此article,**性能选择器**的最佳选择是：

$(“#student-blocks div：first-of-type”);

最后,我将更改代码如下：(http://jsfiddle.net/csdtesting/104cuxxb/)

var studentsblocks = $("#student-blocks");
var el = studentsblocks.find("div:first-of-type");
$(studentsblocks).find("div:gt(0)").hide();
seTinterval(function ()
{
    el
    .hide()
    .next()
    .fadeIn()
    .end()
    .appendTo(studentsblocks);
},4000);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<section id="student-blocks">
  <div>
    <h2 class="animated fadeUp">News Item #1</h2>
    <p "animated fadeIn">lorem</p>
  </div>
  <div>
    <h2 class="animated fadeUp">News Item #2</h2>
    <p "animated fadeIn">lorem</p>
  </div>
  <div>
    <h2 class="animated fadeUp">News Item #3</h2>
    <p "animated fadeIn">lorem</p>
  </div>
</section>

另一种方法是降低动画的帧速率,或进行更改以帮助浏览器渲染引擎(这可能是更改样式或dom的内容).

使用仅CSS的任何PU问题的替代解决方案

为了使它更好,我只使用一个简单的CSs.
我为你的例子做了一个淡出效果：
http://jsfiddle.net/csdtesting/104cuxxb/

仅限CSS实施：

h1,h2,h3 {
  font-family: Tahoma,Arial,sans-serif;
  color: #fff;
  text-shadow: 1px 1px 0px #000000;
  filter: dropshadow(color=#000000,offx=1,offy=1);
}
a:hover {
  color: #0097bc;
}
.wrapper {
  width: 500px;
  margin: 25px auto;
}
.slogan {
  width: 500px;
  height: 90px;
  margin: 25px auto;
  overflow: hidden;
  position: relative;
  border: 1px solid #000;
  BACkground-color: #222;
  -webkit-border-radius: 5px;
  border-radius: 5px;
  -webkit-Box-shadow: inset 0px 2px 2px rgba(0,.5),0px 1px 0px rgba(250,250,.2);
  Box-shadow: inset 0px 2px 2px rgba(0,.2);
  -webkit-transition: BACkground-color 350ms;
  -moz-transition: BACkground-color 350ms;
  transition: BACkground-color 350ms;
}
.slogan span {
  font-family: Tahoma,sans-serif;
  display: inherit;
  width: 100%;
  height: 100%;
  margin: 0;
  font-size: 75%;
  line-height: 5px;
  text-align: center;
  color: #cccccc;
}
.slogan p {
  position: absolute;
  font-family: Tahoma,sans-serif;
  width: 100%;
  height: 100%;
  margin: 0;
  line-height: 50px;
  text-align: center;
  color: #fff;
  text-shadow: 1px 1px 0px #000000;
  filter: dropshadow(color=#000000,offy=1);
  transform: translateX(100%);
  -moz-transform: translateX(100%);
  -webkit-transform: translateX(100%);
}
.slogan p:nth-child(1) {
  animation: left-one 20s ease infinite;
  -moz-animation: left-one 20s ease infinite;
  -webkit-animation: left-one 20s ease infinite;
}
.slogan p:nth-child(2) {
  animation: left-two 20s ease infinite;
  -moz-animation: left-two 20s ease infinite;
  -webkit-animation: left-two 20s ease infinite;
}
.slogan.down p {
  transform: translateY(-100%);
  -moz-transform: translateY(-100%);
  -webkit-transform: translateY(-100%);
}
.slogan.down p:nth-child(1) {
  animation: down-one 20s ease infinite;
  -moz-animation: down-one 20s ease infinite;
  -webkit-animation: down-one 20s ease infinite;
}
.slogan.down p:nth-child(2) {
  animation: down-two 20s ease infinite;
  -moz-animation: down-two 20s ease infinite;
  -webkit-animation: down-two 20s ease infinite;
}
/*================================
	Move the slogan DownWARDs
==================================*/

/** Mozilla Firefox Keyframes **/

@-moz-keyframes down-one {
  0% {
    -moz-transform: translateY(-100%);
  }
  10% {
    -moz-transform: translateY(0);
  }
  40% {
    -moz-transform: translateY(0);
  }
  50% {
    -moz-transform: translateY(100%);
  }
  100% {
    -moz-transform: translateY(100%);
  }
}
@-moz-keyframes down-two {
  0% {
    -moz-transform: translateY(-100%);
  }
  50% {
    -moz-transform: translateY(-100%);
  }
  60% {
    -moz-transform: translateY(0);
  }
  90% {
    -moz-transform: translateY(0);
  }
  100% {
    -moz-transform: translateY(100%);
  }
}
/** Webkit Keyframes **/

@-webkit-keyframes down-one {
  0% {
    -webkit-transform: translateY(-100%);
  }
  10% {
    -webkit-transform: translateY(0);
  }
  40% {
    -webkit-transform: translateY(0);
  }
  50% {
    -webkit-transform: translateY(100%);
  }
  100% {
    -webkit-transform: translateY(100%);
  }
}
@-webkit-keyframes down-two {
  0% {
    -webkit-transform: translateY(-100%);
  }
  50% {
    -webkit-transform: translateY(-100%);
  }
  60% {
    -webkit-transform: translateY(0);
  }
  90% {
    -webkit-transform: translateY(0);
  }
  100% {
    -webkit-transform: translateY(100%);
  }
}

<div class="wrapper">
  <h3>Cool fading text only with css .slogan down class</h3>
  <div class="slogan down">
    <p>News Item #1<span>lorem</span>
    </p>
    <p>News Item #2<span>lorem</span>
    </p>
    <p>News Item #3<span>lorem</span>
    </p>
    <p>News Item #4<span>lorem</span>
    </p>
  </div>
</div>

希望你喜欢它,真的有帮助！