Its my suggestion ,In case of using two Derived Column and one Data Conversion in between source and Destination, it is performance Factor .When we are aware of length of each column then use Fixed width in Flat File Connection Manager and in advanced tab add new column as per requirement and order of the file then change length, datatype and length and map directly with Destination table.

This will reduce Transformations used and give High Performance when loading Billion Records from source file.