How can I read multiple files faster?

How can I read multiple files faster?

in my program I want to read several text files (more than ~800 files),
each with 256 lines and their filenames starting from 1.txt to n.txt, and
store them into a database after several processing steps. My problem is
the data's reading speed. I could speed the program up to about twice the
speed it had before by using OpenMP multithreading for the reading loop.
Is there a way to speed it up a bit more? My actual code is
std::string CCD_Folder = CCDFolder; //CCDFolder is a pointer to a char array
int b = 0;
int PosCounter = 0;
int WAVENUMBER, WAVELUT;
std::vector<std::string> tempstr;
std::string inputline;
//Input
omp_set_num_threads(YValue);
#pragma omp parallel for private(WAVENUMBER) private(WAVELUT)
private(PosCounter) private(tempstr) private(inputline)
for(int i = 1; i < (CCD_Filenumbers+1); i++)
{
//std::cout << omp_get_thread_num() << ' ' << i << '\n';
//Umwandlung und Erstellung des Dateinamens, Öffnen des Lesekanals
std::string CCD_Filenumber = boost::lexical_cast<string>(i);
std::string CCD_Filename = CCD_Folder + '\\' + CCD_Filenumber +
".txt";
std::ifstream datain(CCD_Filename, std::ifstream::in);
while(!datain.eof())
{
std::getline(datain, inputline);
//Processing
};
};
All variables which are not defined here are defined somewhere else in my
code, and it is working. So is there a possibility to speed this code a
bit more up?
Thank you very much!