Why the recursive list is so slow in haskell？

I am fresh in haskell, and I defined a func in Haskell :

febs :: (Integral a)=> a -> a
febs n 
    | n<=0 =0
    | n==1 =1
    | n==2 =1
    | otherwise =febs(n-1)+febs(n-2)

but, it runs so slow, and when I do "febs 30", it will take about 10s, and I do the same func in C++, it runs very fast.

int febs(int n)
{
    if(n == 1 || n ==2)
    {
        return 1;
    }
    return febs(n-1)+febs(n-2);
}

Is there any way to promote my haskell func speed?