装箱耗时居然是拆箱的30倍左右

using System;

namespace 第03章_03
{
    /**//// <summary>
    /// excersize 的摘要说明。
    /// </summary>
    public class excersize
    {
        static void Main()
        {
            int[] source=new int[5000000];
            object[] target = new object[5000000];
            long lStart,lEnd;

            lStart=System.DateTime.Now.Ticks;
            for(int i=0;i<source.Length;i++)
                target[i]=source[i];//装箱操作
            lEnd=System.DateTime.Now.Ticks;
            Console.WriteLine("装箱耗时微毫秒：{0}",lEnd-lStart);

            lStart=System.DateTime.Now.Ticks;
            for(int i=0;i<source.Length;i++)
                source[i]=(int)target[i];//拆箱操作
            lEnd=System.DateTime.Now.Ticks;
            Console.WriteLine("拆箱耗时微毫秒：{0}",lEnd-lStart);
        }
    }
}
/**//*
装箱耗时微毫秒：9400000
拆箱耗时微毫秒：350000
*/