faster method for setdiff

I am using setdiff function for deleting same rows.

 C = setdiff(A,B,'rows')

It takes about 84.9% of time for my entire code which consumes a lot of time. Is there a faster way for setdiff function?

[Kirby Fears]

Yuang,

What kind of data is in A and B?

Is one a superset of the other?

[Walter Roberson]

What is your data type? Numeric? Categorical? Table?