List<T> vs yield return in performance

public void ListAndYield()
{
    const int count = 10000000;

    var sw = new Stopwatch();
    sw.Start();
    var list = ByList(count).ToArray();
    sw.Stop();
    Debug.WriteLine(string.Format(
        "List {1:#,##0} items: {0:#,##0.000} ms", sw.ElapsedMilliseconds, list.Count()));

    sw.Reset();
    sw.Start();
    list = ByYield(count).ToArray();
    sw.Stop();
    Debug.WriteLine(string.Format(
        "Yield {1:#,##0} items: {0:#,##0.000} ms", sw.ElapsedMilliseconds, list.Count()));
}

private IEnumerable<int> ByList(int count)
{
    var ret = new List<int>();
    for(var i = 0; i < count; i++)
    {
        ret.Add(i);
    }
    return ret;
}

private IEnumerable<int> ByYield(int count)
{
    for(var i = 0; i < count; i++)
    {
        yield return i;
    }
}