pbmclapply is very much faster than mclapply....

dear members,
                            I am using pbmclapply function to check the progress of my functions that is to be run in parallel (with function mclapply).

To my amazement, I found out that pbmclapply is more than 3X faster than mclapply!!!

Any idea on why this is so?

very many thanks for your time and effort...
yours sincerely,
AKSHAY M KULKARNI