Hi Murali,
you can try below steps.
Step 1- if possible you use table partioning for the source table .
Step 2 - Make D.O.P. value =2 (or that support for performance increasing, every time increasing the DOP will not work also 
for performance increase ).
Step 3 - apply parallel thread into target file option.
Please try these steps and update the thread
Regards,
Shiva Sahu