Performance point of view

Hi every one,

I am new to XI . I have a small doubt in Mappings.

In XI we have 4 types of mappings:

1.Graphical mapping

2.XSLT mapping,

3.Java Mapping

4.ABAP mapping

In case of performance point of view which one is best .

Plz explain me in details .

I will give full points for correct answers.

Thanks and Regards,

P.Naganjana Reddy