using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Diagnostics;
using System.Globalization;
using System.Linq;

namespace test
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Press to go");
            Console.ReadKey();
            var ids = new List<int> { 1, 11, 35, 171, 49, 27, 285, 290, 335, 440, 404, 34 };

            const string con = "Data Source='SERVER\\SQL2008R2'; Initial Catalog=test' ;Persist Security Info='True'; User ID='sa'; Password=****;";
            var rnd = new Random();
            var linq = new DataClassesDataContext();
            var sw = Stopwatch.StartNew();
            for (int i = 0; i < ids.Count; i++)
            {
                var res = linq.Items.Single(x => x.Id == ids[i]);
            }
            Console.WriteLine(sw.ElapsedMilliseconds);

            sw = Stopwatch.StartNew();

            using (var sql = new SqlConnection(con))
            {
                sql.Open();
                for (int i = 0; i < ids.Count; i++)
                {

                    using (var cmd = new SqlCommand("SELECT * FROM Catalog.Product where ProductId=@ProductId", sql))
                    {
                        cmd.Parameters.AddWithValue("@ProductId", ids[i]);
                        using (var reader = cmd.ExecuteReader())
                        {
                            while (reader.Read())
                            {
                                var data = new Item
                                               {
                                                   Id = (int)reader["Id "],
                                                   Serial= (string)reader["Serial"],
                                                   Name = (string)reader["Name"],
                                                   Ratio = Convert.ToDouble(reader["Ratio"], CultureInfo.InvariantCulture),
                                                   Discount = Convert.ToDecimal(reader["Ratio"], CultureInfo.InvariantCulture),
                                                   Weight = Convert.ToDecimal(reader["Weight"], CultureInfo.InvariantCulture),
                                                   ItemSize = (string)reader["ItemSize "],
                                                   IsFreeShipping = (bool)reader["IsFreeShipping"],
                                                   ItemsSold = (int)reader["ItemsSold"],
                                                   BriefDescription = (string)reader["BriefDescription"],
                                                   Description = (string)reader["Description"],
                                                   Enabled = (bool)reader["Enabled"],
                                                   Recomended = (bool)reader["Recomended"],
                                                   New = (bool)reader["New"],
                                                   BestSeller = (bool)reader["BestSeller"],
                                                   OnSale = (bool)reader["OnSale"],
                                                   OrderByRequest = (bool)reader["OrderByRequest"],
                                                   HirecalEnabled = (bool)reader["HirecalEnabled"],
                                                   UrlPath = (string)reader["UrlPath"]
                                               };
                            }
                        }
                    }
                }
            }
            Console.WriteLine(sw.ElapsedMilliseconds);
            Console.ReadKey();
        }

        public class Item
        {
            public int Id { get; set; }
            public string Serial{ get; set; }
            public string Name { get; set; }
            public double Ratio { get; set; }
            public decimal Discount { get; set; }
            public decimal Weight { get; set; }
            public string ItemSize { get; set; }
            public bool IsFreeShipping { get; set; }
            public int ItemsSold { get; set; }
            public string BriefDescription { get; set; }
            public string Description { get; set; }
            public bool Enabled { get; set; }
            public bool Recomended { get; set; }
            public bool New { get; set; }
            public bool BestSeller { get; set; }
            public bool OnSale { get; set; }
            public bool OrderByRequest { get; set; }
            public bool HirecalEnabled { get; set; }
            public string UrlPath { get; set; }
        }
    }
}

BestSeller = (bool)reader["BestSeller"],