Is accessing the elements of a char* or std::string faster?

I have seen char* vs std::string in c++, but am still wondering if accessing the elements of a char* is faster than std::string.

If you need to know, the char*/std::string will contain less than 80 characters, but I would like to know a cutoff if there is one.

I would also like to know the answer to this question for different compilers and different Operating Systems, if there is a difference.

Thanks in advance!

(Note: If this doesn't meet the help center, please let me know how I can reword it before down-voting)