setting initial capacity in Arraylist is not a good idea?

Question

I am a java developer for three years but never thought about the underlying performance costs between different implementations of lists. That s why I make a benchmark like :

private static int N = 10000000;
public static void main(String args[]){
    doSt(new ArrayList<String>());
    doSt(new ArrayList<String>(N));
    doSt(new LinkedList<String>());
}

private static List<String> doSt(List<String> fizzbuzz) {
    long l = System.currentTimeMillis();
    int counter = 1;
    while(counter <= N){
        fizzbuzz.add("aa");
        counter++;
    }
    long l2 = System.currentTimeMillis();
    System.out.println("time spent " + (l2-l));
}

and I see

time spent 148,

time spent 33,

time spent 198,

meaning that

time performance(ArrayList with initial capacity) > time performance(ArrayList) > time performance(LinkedList).

LinkedList and ArrayList is pretty close, since insertion is O(1) in both implementations, I am not bothered by the small difference.

BUT, if I change the implementation like :

private static int N = 10000000;
public static void main(String args[]){
    doStWithIfElse(new ArrayList<String>());
    doStWithIfElse(new ArrayList<String>(N));
    doStWithIfElse(new LinkedList<String>());
}

private static List<String> doStWithIfElse(List<String> fizzbuzz) {
    long l = System.currentTimeMillis();
    int counter = 1;
    while(counter <= N){
        if (counter %3 == 0 && counter %5 == 0){
            fizzbuzz.add("FizzBuzz");
        }
        else if (counter %3 == 0){
            fizzbuzz.add("Fizz");
        }
        else if (counter %5 == 0){
            fizzbuzz.add("Buzz");
        }
        else{
            fizzbuzz.add(Integer.toString(counter));
        }            counter++;
    }
    long l2 = System.currentTimeMillis();
    System.out.println("time spent " + (l2-l));
}

then,

time spent 516,

time spent 8452,

time spent 6808,

Then All of a sudden, ArrayList with the initial capacity becomes the poorest performer and ArrayList without the initial capacity beats them all with a big margin.

That really confused me a lot. What is the reason of performance changes when I introduce the if else statements?