why the sdk4 use more Memory than sdk3

the demo is sample.

but why the sdk4 use more Memory than sdk3?

sdk3 use 57M ,

sdk4 use 75M

 

sdk3:

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" minWidth="955" minHeight="600">
 
 <mx:Button label="12313" />
 
 <mx:TextArea width="100" height="100" text="12312" />
 
 
</mx:Application>

sdk4:

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"

      xmlns:s="library://ns.adobe.com/flex/spark"
      xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600"
      >
 
 <fx:Script>
  <![CDATA[
   
   
  ]]>
 </fx:Script>
 
 <fx:Declarations>
  <!-- 將非可視元素（例如服務、值對象）放在此處 -->
 </fx:Declarations>
 
 <s:Button label="12313" />
 
 <s:TextArea width="100" height="100" text="12312" />
 
 
 
</s:Application>