Parallel SqlDataReader and reader.Read()

Question

I want to do a consult in Parallel mode, or which is the better way to do the consult to SQL.

The consult spends 3 minutes doing 7 cycles from 7 stocks, but I need that spend less time, maybe by doing the 7 consults at the same time and return the result.

My problem with the code is that reader.Read() maybie shock between the consults.

 <code>

List<List<clsExistenciaA>> ListaExistencia = new List<List<clsExistenciaA>>(); 
SqlConnection objConexion = new SqlConnection();//conexion a sql 
try {     
objConexion.ConnectionString = 
@"Database=DataDB;Data Source=local;User 
Id=sa;Password=20011$;MultipleActiveResultSets=True";     
objConexion.Open(); } catch { MessageBox.Show("No se puede conectar al servidor");
 }  try { string almacen; int i = 0; foreach(clsExistenciaA A in AlmaceneS) 
{ //Parallel.ForEach(AlmaceneS, clsExistenciaA => //{ //    
lock (AlmaceneS) //    { //        
almacen = clsExistenciaA.CodigoAlm;          
almacen = A.CodigoAlm; SqlCommand comm = new SqlCommand();//crea command   
       comm.Connection = objConexion;// se agrega la conexion al comando 
     
comm.CommandType = CommandType.Text;// se define el tipo de comando string 
sql = "";           sql = "select c_codigo_alm, v_nombre_alm from invalmacen 
(nolock) where c_pedido_alm='almacen'";          comm.CommandTimeout = 1000; 
         comm.CommandText = sql;// se agrega la consulta a el comando 
SqlDataReader reader = comm.ExecuteReader();
// se ejecuta el comando en un data reader 

ListaExistencia.Add(new List<clsExistenciaA>()); 
string piezaN = "0"; 
string kiloN = "0"; 

while(reader.Read()) { if (reader["pieza"].ToString() != "") {                 
piezaN = reader["pieza"].ToString(); } 
if (reader["kilos"].ToString() != "") {                  
kiloN = reader["kilos"].ToString(); } 
ListaExistencia[i].Add(new clsExistenciaA() {                  
pro = reader["pro"].ToString(),                  
nompro = reader["v_nombre_pro"].ToString(),                  
pieza = Math.Round(double.Parse(piezaN), 2),                  
kilos = Math.Round(double.Parse(kiloN), 2), 
CodigoAlm = almacen, }); // se agregan los datos a un Ilist }            

reader.Close(); } ////} //}); 

return ListaExistencia; }</code>