Use this syntax for parallel bulk copy, when using several simultaneous sessions.
bcp table_name[:partition_number | partrition_name] in file_name -Pmypassword
bcp_r database_name..table_name partition partition_number1 [, partition_number2 ...] in file_name1 [,file_name2 ....] -U[username] -P[password] -S[servername]
bcp database_name..table_name partition partition_number1 [, partition_number2 ...] in file_name1 [,file_name2 ....] -U[username] -P[password] -S[servername]