We can specify initial Capacity for List , Maps and Set Collection types.
Generally if we consider at hardware level, it is fast to access bunch of bits in Power of 2. (2^i) Eg. 8 Bytes, 64 Bytes, ...
So, if we maintain Collection size in Power of 2 then does it increase my Application performance which is using no of collection types.
No. Java handles memory alignment internally, you should not be worrying about that yourself. Whatever you think you can do, Java does it better. A lot better. Write dumb code in stead to help the JVM optimize.