concurrent包中atomic中的怪異現象

呃。。記錄一個比較奇怪的現象。。。待於以後實際開發中測試後選擇

package cn.itcast.heima2;

import java.util.concurrent.atomic.AtomicInteger;  
public class AtomicIntegerCompareTest {  
    private int value;  
      
    public AtomicIntegerCompareTest(int value){  
        this.value = value;  
    }  
      
    public synchronized int increase(){  
        return value++;  
    }  
      
	public static void main(String args[]){  
        long start = System.currentTimeMillis();  
          
        AtomicIntegerCompareTest test = new AtomicIntegerCompareTest(0);  
        for( int i=0;i< 1000000;i++){  
            test.increase();  
        }  
        long end = System.currentTimeMillis();  
        System.out.println("time elapse:"+(end -start));  
          
        long start1 = System.currentTimeMillis();  
        
        AtomicInteger atomic = new AtomicInteger(0);  
        
        for( int i=0;i< 1000000;i++){  
            atomic.incrementAndGet(); 
        }  
        long end1 = System.currentTimeMillis();  
        System.out.println("time elapse:"+(end1 -start1) );  
          
        /*
         * JRE 1.6.0_12（32位）:
         * time elapse:34
         * time elapse:14
         * 
         * jdk1.7.0_51（64位）：
         * time elapse:17
         * time elapse:19
         */

    }  
}

在7中concurrent包中的atomic竟然沒有了高效執行的優勢?????放在以後測試後決定使用哪個吧。。。