Read internal table using secondary key and binary search

Hi, I just checking related to read internal table using secondary key and using binary search.

I have taken measurement for both processing block.

Binary search on sorted internal table taking less time compare to secondary key in read table statement.

Kindly suggest which one is preferable in which scenario.

if secondary key takes too much time compare to read table binary search then why we need of secondary key??

Thanks & Regards

Kishan Rana