const int TEST_AMOUNT = 1;

var arr = new int[TEST_AMOUNT];
for (int i = 0; i < arr.Length; i++) arr[i] = i + 1;

var testList = new List<int>();

var s = new Stopwatch();

s.Start ();
foreach (int i in arr) {
    if (i % 3 == 0) testList.Add (i);
}
s.Stop (

Console.WriteLine ("Foreach:\t{0} ticks", s.ElapsedTicks);

s.Restart ();
var testLinq =
        from i in arr
        where i % 3 == 0
        select i;
s.Stop ();

Console.WriteLine ("Linq:\t\t{0} ticks", s.ElapsedTicks);