Fibonacci number calculators speed comparison

public class FibonacciSeries {

    public static void main(String[] args) {
        long startTime, endTime;
        double allTime;

        System.out.println("printFib fut...");
        startTime = System.nanoTime();
        System.out.print(1);
        printfib(40);
        endTime = System.nanoTime();
        allTime = (endTime - startTime);
        System.out.println("\n eltelt idő: " + allTime + " ns");

        System.out.println("\nrekurzív fib fut...");
        startTime = System.nanoTime();
        System.out.println("eredmény: " + fib(40));
        endTime = System.nanoTime();
        allTime = (endTime - startTime);
        System.out.println("eltelt idő: " + allTime + " ns");

        System.out.println("\n ciklusos fib2 fut...");
        startTime = System.nanoTime();
        System.out.println("eredmény: " + fib2(40));
        endTime = System.nanoTime();
        allTime = (endTime - startTime);
        System.out.println("eltelt idő: " + allTime + " ns");


    }

    private static int fib(int a){
        if(a == 0 || a == 1){
            return a;
        }
        return fib(a-1) + fib(a - 2);
    }


    static int n1 = 0, n2 = 1, n3 = 0;
    private static void printfib(int a){
            if(a > 0){
                n3 = n1 + n2;
                n1 = n2;
                n2 = n3;
                System.out.print(", " + n3);
                printfib(a - 1);
            }
    }

    private static int fib2(int n){
        int F = 0;
        int prev = 1;
        int next;
        for(int i=0; i < n; i++){
            next = F + prev;
            prev = F;
            F = next;
        }
        return F;
    }

}