读写文件时缓冲区多大好呢？我来告诉大家哈

今天测试了一下读写文件时缓冲区多大合适的问题，缓冲区的大小并非我之前想的那样越大越好，测试后发现竟然是64KB时最快啊。下面是测试用的代码大家看一下有问题请指正：

  HANDLE h = CreateFile(m_file_name,FILE_ALL_ACCESS,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL); if (h==INVALID_HANDLE_VALUE) { return GetLastError(); } static char read_buff[READ_SIZE]; DWORD tick_count = GetTickCount(); while(1) { DWORD len = 0; BOOL ret = ReadFile(h,read_buff,READ_SIZE,&len,NULL); if (!ret) { return GetLastError(); } else if (len == 0) { break; //文件结束了 } } DWORD time = GetTickCount() - tick_count; sprintf(read_buff,"time = %lu./n",time); OutputDebugString(read_buff); CloseHandle(h);