private static Stopwatch InsertUsingSqlBulkCopy(List list)
 {
 Stopwatch stopWatch = new Stopwatch();
 stopWatch.Start();
 DataTable dt = new DataTable();
 dt.Columns.Add("ID");
 dt.Columns.Add("UserName");
 for (int i = 0; i < list.Count; i++)
 {
 DataRow row = dt.NewRow();
 row["ID"] = list[i].ID;
 row["UserName"] = list[i].UserName;
 dt.Rows.Add(row);
 }
 using (SqlConnection con = new SqlConnection(connStr2))
 {
 con.Open();
 using (SqlBulkCopy bulkCopy = new SqlBulkCopy(con))
 {
 try
 {
 bulkCopy.DestinationTableName = "dbo.T_UserName";
 bulkCopy.ColumnMappings.Add("ID", "ID");
 bulkCopy.ColumnMappings.Add("UserName", "UserName");
 bulkCopy.WriteToServer(dt);
 }
 catch (Exception ex)
 {
 Console.WriteLine(ex.ToString());
 }
 finally { con.Close(); }
 }
 }
 stopWatch.Stop();
 return stopWatch;
 }

private static Stopwatch InsertUsingLINQ(List _list)
 {
 Stopwatch stopWatch = new Stopwatch();
 stopWatch.Start();
 DataClasses1DataContext dataContext = new DataClasses1DataContext();
 dataContext.T_Users.InsertAllOnSubmit(_list);
 dataContext.SubmitChanges();
 stopWatch.Stop();
 return stopWatch;
 }