static void Main(string[] args) { var products = new OrderedMultiDictionary<int, string>(false); Console.WriteLine("Adding products..."); for (int i = 0; i < 500000; i++) { products.Add(i,"product"+i); } Console.WriteLine("Done!"); Console.WriteLine(); Console.WriteLine("Performing queries..."); for (int i = 0; i < 10000; i++) { var prodictsInRange = products.Where(x => x.Key >= i && x.Key <= i * 50); } Console.WriteLine("Done!"); }