C#的性能到底有多差？

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C#的性能到底有多差？

2013年04月26日 ⁄ 综合 ⁄ 共 6143字 ⁄ 字号小中大 ⁄ 评论关闭

这篇文章带领大家来看看c#的性能问题。当然了，作为比较的选手是c/c++。

首先说说测试环境：

操作系统：win7 旗舰版

内存：2GB

硬盘：160GB

处理器：Intel Pentium Dual CPU T2330 @ 1.60GHZ

本文打算基于以下几个方面讨论：

1.CPU使用情况；

2.内存使用情况；

3.基本类型的四则运算能力；

4.数学函数运算能力；

5.I/O操作能力；

6.数组运算能力；

7.异常处理能力；

8.STL vs FCL；

9.算法HeapSort；

10.矩阵乘；

11.嵌套for循环；

12.字符串连接。

接下来，我们一个一个详细地说：（注，测试程序都是直接运行编译后的exe）

1.CPU使用情况

在程序的整个运行过程中，两者的CPU占用情况都在50%上下浮动，算是不分上下。

2.内存使用情况

这里列一

组程序执行过程中我记录的数据：

c/c++：216kb，832kb，904kb，944kb，1336kb。

c#：1972kb，1980kb，2000kb，2372kb，3024kb，5156kb。

通过这组数据，不难发现，在内存使用方面c#可算是一败涂地。注：

希望有人能解释下c#为什么会出现这种一路飙升的情况呢？！

3.基本类型的四则运算能力

费话不多说了，上代码：（注，所有的图中时间单位均为毫秒ms）

c/c++的：

针对int的

 1 double intArithmetic(">int intMax)
 2 {
 3     double elapsedTime;
 4     clock_t stopTime;
 5     int intResult = 1;
 6     int i = 1;
 7 
 8     clock_t startTime = clock();
 9     while (i < intMax)
10     {
11         intResult -= i++;
12         intResult += i++;
13         intResult *= i++;
14         intResult /= i++;
15     }
16     stopTime = clock();
17 
18     elapsedTime = (stopTime - startTime) / (CLOCKS_PER_SEC / (double) 1000.0);
19     printf("Int arithmetic elapsed time: %1.0f ms with intMax of %ld\n", elapsedTime, intMax);
20     printf(" i: %d\n", i);
21     printf(" intResult: %d\n", intResult);
22     return elapsedTime;
23 }

c#的：

针对int的

 1 static long intArithmetic(int intMax)
 2         {
 3             long elapsedMilliseconds;
 4             int intResult = 1;
 5             int i = 0;
 6 
 7             stopwatch.Start();
 8             while (i < intMax)
 9             {
10                 intResult -= i++;
11                 intResult += i++;
12                 intResult *= i++;
13                 intResult /= i++;
14             }
15             elapsedMilliseconds = stopwatch.ElapsedMilliseconds;
16             stopwatch.Reset();
17 
18             Console.WriteLine("Int arithmetic elapsed time: " + elapsedMilliseconds + 
19                 " ms with max of " + intMax);
20             Console.WriteLine(" i: " + i);
21             Console.WriteLine(" intResult: " + intResult);
22             return elapsedMilliseconds;
23         }

对比结果见下图：

c/c++的：

针对double的

 1 double doubleArithmetic(double doubleMin, double doubleMax)
 2 {
 3     double elapsedTime;
 4     clock_t stopTime;
 5     clock_t startTime = clock();
 6 
 7     double doubleResult = doubleMin;
 8     double i = doubleMin;
 9     while (i < doubleMax)
10     {
11         doubleResult -= i++;
12         doubleResult += i++;
13         doubleResult *= i++;
14         doubleResult /= i++;
15     }
16 
17     stopTime = clock();
18     elapsedTime = (stopTime - startTime) / (CLOCKS_PER_SEC / (double) 1000.0);
19     printf("Double arithmetic elapsed time: %1.0f ms with doubleMin %.15f, doubleMax %.15f\n", elapsedTime, doubleMin, doubleMax);
20     printf(" i: %f\n", i);
21     printf(" doubleResult: %.15f\n", doubleResult);
22     return elapsedTime;
23 }

c#的：

针对double的

 1 static long doubleArithmetic(double doubleMin, double doubleMax)
 2         {
 3             long elapsedMilliseconds;
 4             double doubleResult = doubleMin;
 5             double i = doubleMin;
 6 
 7             stopwatch.Start();
 8             while (i < doubleMax)
 9             {
10                 doubleResult -= i++;
11                 doubleResult += i++;
12                 doubleResult *= i++;
13                 doubleResult /= i++;
14             }
15             elapsedMilliseconds = stopwatch.ElapsedMilliseconds;
16             stopwatch.Reset();
17         
18             Console.WriteLine("Double arithmetic elapsed time: " + elapsedMilliseconds + 
19                 " ms with min of " + doubleMin + ", max of " + doubleMax);
20             Console.WriteLine(" i: " + i);
21             Console.WriteLine(" doubleResult: " + doubleResult);
22             return elapsedMilliseconds;
23         }

对比结果见下图：

c/c++的：

针对long的

 1 double longArithmetic(long long longMin, long long longMax)
 2 {
 3     double elapsedTime;
 4     clock_t stopTime;
 5     clock_t startTime = clock();
 6 
 7     long long longResult = longMin;
 8     long long i = longMin;
 9     while (i < longMax)
10     {
11         longResult -= i++;
12         longResult += i++;
13         longResult *= i++;
14         longResult /= i++;
15     }
16 
17     stopTime = clock();
18     elapsedTime = (stopTime - startTime) / (CLOCKS_PER_SEC / (double) 1000.0);
19     printf("Long arithmetic elapsed time: %1.0f ms with longMax %I64d\n", elapsedTime, longMax);
20     printf(" i: %I64d\n", i);
21     printf(" longResult: %I64d\n", longResult);
22     return elapsedTime;
23 }

c#的：

针对long的

 1 static long longArithmetic(long intMin, long intMax)
 2         {
 3             long elapsedMilliseconds;
 4             long intResult = intMin;
 5             long i = intMin;
 6 
 7             stopwatch.Start();
 8             while (i < intMax)
 9             {
10                 intResult -= i++;
11                 intResult += i++;
12                 intResult *= i++;
13                 intResult /= i++;
14             }
15             elapsedMilliseconds = stopwatch.ElapsedMilliseconds;
16             stopwatch.Reset();
17         
18             Console.WriteLine("long arithmetic elapsed time: " + elapsedMilliseconds + 
19                 " ms with min of " + intMin + ", max of " + intMax);
20             Console.WriteLine(" i: " + i);
21             Console.WriteLine(" intResult: " + intResult);
22             return elapsedMilliseconds;
23         }

对比结果见下图：

通过以上数据，发现两者对基本数据类型的操作性能差不多，属于同一个数量级。

同时，注意到，c#针对int型的性能要优于c/c++。

4.数学函数的运算能力

c/c++的：

常用数学函数

 1 double trig(double trigMax)
 2 {
 3     double elapsedTime;
 4     clock_t stopTime;
 5     clock_t startTime = clock();
 6 
 7     double sine;
 8     double cosine;
 9     double tangent;
10     double logarithm;
11     double squareRoot;
12 
13     double i = 0.0;
14     while (i < trigMax)
15     {
16         sine = sin(i);
17         cosine = cos(i);
18         tangent = tan(i);
19         logarithm = log10(i);
20         squareRoot = sqrt(i);
21         i++;
22     }
23 
24     stopTime = clock();
25     elapsedTime = (stopTime - startTime) / (CLOCKS_PER_SEC / (double) 1000.0);
26     printf("Trig elapsed time: %1.0f ms with max of %1.0f\n", elapsedTime, trigMax);
27     printf(" i: %f\n", i);
28     printf(" sine: %.15f\n", sine);
29     printf(" cosine: %.15f\n", cosine);
30     printf(" tangent: %.15f\n", tangent);
31     printf(" logarithm: %.15f\n", logarithm);
32     printf(" squareRoot: %.15f\n", squareRoot);
33     return elapsedTime;
34 }

c#的：

常用数学函数

 1 static long trig(double trigMax)
 2         {
 3             long elapsedMilliseconds;
 4         
 5             double sine = 0.0D;
 6             double cosine = 0.0D;
 7             double tangent = 0.0D;
 8             double logarithm = 0.0D;
 9             double squareRoot = 0.0D;        
10             double i = 0.0D;
11 
12             stopwatch.Start();
13             while(i < trigMax)
14             {
15                 sine = Math.Sin(i);
16                 cosine = Math.Cos(i);
17                 tangent = Math.Tan(i);
18                 logarithm = Math.Log10(i);
19                 squareRoot = Math.Sqrt(i);
20                 i++;
21             }
22             elapsedMilliseconds = stopwatch.ElapsedMilliseconds;
23             stopwatch.Reset();
24         
25             Console.WriteLine("Trig elapsed time: " + elapsedMilliseconds + 
26                 " ms with max of " + trigMax);
27             Console.WriteLine(" i: " + i);
28             Console.WriteLine(" sine: " + sine);
29             Console.WriteLine(" cosine: " + cosine);
30             Console.WriteLine(" tangent: " + tangent);
31             Console.WriteLine(" logarithm: " + logarithm);
32             Console.WriteLine(" squareRoot: " + squareRoot);
33             return elapsedMilliseconds;
34         }

对比结果如下图：

通过数据，我们发现c#在计算sin、cos、tan、log、sqrt等数学函数方面明显

优于c/c++。大家以后注意了哦……

5.I/O操作能力

c/c++的：

写文件、读文件

 1 double io(int ioMax)
 2 {
 3     double elapsedTime;
 4     clock_t stopTime;
 5     clock_t startTime = clock();
 6 
 7     FILE *stream;
 8     stream = fopen("F:\\TestC.txt", "w");
 9     int i = 0;
10     while (i++ < ioMax)
11     {
12         fputs("abcdefghijklmnopqrstuvwxyz1234567890abcdefghijklmnopqrstuvwxyz1234567890abcdefgh\n", stream);
13     }
14     fclose(stream);
15 
16     char readLine[100];
17     stream = fopen("F:\\TestC.txt", "r");
18     i = 0;
19     while (i++ < ioMax)
20     {
21         fgets(readLine, 100, stream);
22     }
23     fclose(stream);
24 
25     stopTime = clock();
26     elapsedTime = (stopTime - startTime) / (CLOCKS_PER_SEC / (double) 1000.0);
27     printf("I/O elapsed time: %1.0f ms with max of %ld\n", elapsedTime, ioMax);
28     printf(" i: %d\n", i);
29     printf(" readLine: %s\n", readLine);
30 
31     return elapsedTime;
32 }

c#的：

写文件、读文件

 1 static long io(int ioMax)
 2         {
 3             long elapsedMilliseconds;
 4         
 5             String fileName = "F:\\TestCSharp.txt";
 6             String textLine