本文转自:https://www.cnblogs.com/wuchang/archive/2006/12/07/584997.html
一直以来只知道托管代码的效率要比非托管代码低,至于低多少也没有可参考的数据。今天在csdn看到的英特尔多核平台编程优化大赛的广告,把里面的代码下载回来,分别用非托管c/托管cpp/c#做了个简略的性能测试,不比不知道,一比吓了一跳。且看数据说话。
第一步:原始代码如:
执行结果如下:
执行时间4.609s。
第二步:托管
新建一个 C++ CLR Console Aplication,命名为mcpp。打开mcpp.cpp文件,将原始代码粘贴进来即可(代码太长这里就不贴出来了,可以在全贴下面的下载全部源码)。
执行结果如下:
执行时间:15.1720s。
第二步:c#
笔者将原始代码翻译成CS代码,如下:
using System.Collections.Generic;
using System.Text;


namespace cs

class Program

private const int RAND_MAX = 0x7fff;
private const int NPARTS = 1000;
private const int NITER = 201;
private const int DIMS = 3;
private double pot;
private double distx, disty, distz, dist;
private Random random = new Random(Environment.TickCount);
private double[][] r = new double[DIMS][];

public void main()

int i;
int start, stop;

for (int ii = 0; ii < DIMS; ii++)

= new double[NPARTS];
}

initPositions();
updatePositions();

start = Environment.TickCount;
for (i = 0; i < NITER; i++)

= 0.0;
computePot();
if (i % 10 == 0)
Console.WriteLine("{0}: Potential: {1:##########.###}", i, pot);
updatePositions();
}
stop = Environment.TickCount;
Console.WriteLine("Seconds = {0:##########.#########}", (double)(stop - start)/1000);
}

private void computePot()

int i, j;

for (i = 0; i < NPARTS; i++)

for (j = 0; j < i - 1; j++)

= Math.Pow((r[0][j] - r[0][i]), 2);
disty = Math.Pow((r[1][j] - r[1][i]), 2);
distz = Math.Pow((r[2][j] - r[2][i]), 2);
dist = Math.Sqrt(distx + disty + distz);
pot += 1.0 / dist;
}
}
}

private void updatePositions()

int i, j;

for (i = 0; i < DIMS; i++)
for (j = 0; j < NPARTS; j++)
r[i][j] -= 0.5 + ((double)random.Next(RAND_MAX)/(double)RAND_MAX);
}

private void initPositions()

int i, j;
for (i = 0; i < DIMS; i++)
for (j = 0; j < NPARTS; j++)
r[i][j] = 0.5 + ((double)random.Next(RAND_MAX)/(double)RAND_MAX);
}

static void Main(string[] args)

= new Program();
p.main();
Console.ReadLine();

}
}
}























































































执行结果如下: