3 文件读写 计时 我的烂电脑在1S钟能写70多MB的数据

#include <stdio.h>
#include <time.h>

int main ()
{
 FILE * pFile;
 int i;
 pFile = fopen ( "myfile.txt" , "wb" );
 char buffer[8*1024] = {0};
 double d ;clock_t start=0;clock_t finish=0;
    int j=0;
 start = clock(); //计时开始
 for (j=0;j<9200;j++)
 {
  
    

  for(i=0;i<8*1024;i++) buffer[i]=i;)//添加8K的数据
     // printf("%d/n",sizeof(buffer));

  fwrite (buffer , sizeof(buffer), 1 , pFile );//每次写8K的数据
    // printf("%d  ",j);

 }
     finish = clock(); //计时结束
  d = (double)(finish - start  ) / CLOCKS_PER_SEC;
  printf("%f\n",d);
  printf("%f\n",start/ CLOCKS_PER_SEC);
    printf("%f\n",finish/ CLOCKS_PER_SEC);
 fclose (pFile);
 return 0;
}