I make windows form application c# vs 2015 to generate 2d matrix barcodes for pharmaceutical company manufacture medicine .
my problem when i make order to generate 2d matrix barcode for 200000 barcode and save barcodes in hard disk take 20 minutes
How to minimize 20 minutes to 8 minutes when generate and saving 200000 barcode ?
my code under button as following

I attached  libarary for datamatrix encoding with message

library data matrix

Class1 CLS =newClass1();
DataTable dt = CLS.ShowalldataSerial(textBox4.Text);
string baseText ="UserID"+ dt.Rows[0][0]+"FirmName"+ dt.Rows[0][1]+"OrderNo"+ dt.Rows[0][2]+"BtachNo"+ dt.Rows[0][3]+"Quantity"+ dt.Rows[0][4]+"ProductName"+ dt.Rows[0][5]+"SerialNo";
Color foregroundColor =Color.FromName(comboBox1.SelectedItem.ToString());
int serialsToGenerate =Convert.ToInt32(textBox1.Text);
Parallel.For(0, serialsToGenerate, index=>
{
stringSerial= SRL.Rnd().ToString();
string txt = baseText +Serial;
// WARNING HERE
 DM_Encoder dm =new DM_Encoder();
 dm.DM(txt, foregroundColor,Color.White).Save(root +"\\"+Serial+".emf",System.Drawing.Imaging.ImageFormat.Emf);
});