Sleep(1) x Sleep(0)

ThreadSleep.cs

// Code From http://www.bluebytesoftware.com/blog/PermaLink,guid,1c013d42-c983-4102-9233-ca54b8f3d1a1.aspx
    using System;
    using System.Diagnostics;
    using System.Threading;

    class Program {
        public static volatile int x = 0;

        public static void Main() {
            Stopwatch sw = new Stopwatch();
            sw.Start();

            SpawnWork();
            while (x == 0) {
                Thread.Sleep(0);
            }

            sw.Stop();
            Console.WriteLine("Sleep(0) = {0}", sw.Elapsed);

            x = 0;

            sw.Reset();
            sw.Start();

            SpawnWork();
            while (x == 0) {
                Thread.Sleep(1);
            }

            sw.Stop();
            Console.WriteLine("Sleep(1) = {0}", sw.Elapsed);
        }

        private static void SpawnWork() {
            ThreadPool.QueueUserWorkItem(delegate {
                Thread.CurrentThread.Priority = ThreadPriority.BelowNormal;
                x = 1;
            });
        }
    }