K最小选择算法- O (n + K log n) vs (n log K) K << n。

I'm asking this in regards to Top K algorithm. I'd think that O(n + k log n) should be faster, because well.. for instance if you try plugging in k = 300 and n = 100000000 for example, we can see that O(n + k log n) is smaller.I'm asking this in regards to Top K algorithm.