using System;

using System.Collections.Generic;

using System.Threading;

using System.Threading.Tasks;

public class Program {

    public static void Main() {

        var lstObj = new List<int> { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 };

        Parallel.ForEach(lstObj, obj => MetodoX(obj));

        Console.WriteLine("Fim"); //aqui poderia ser o MetodoY()

    }

​

    public static void MetodoX(int obj) {

        Console.WriteLine($"ThreadID: {Thread.CurrentThread.ManagedThreadId, 3}, Valor: {obj}");

    }

}