Db2 insert load's data slowly if we have load scheduled for tables in parallel. There is no such situation that one table being accessed by another table and lock issues. All are independent tables. Individually completes data load fast soon than in parallel.Is there any parameter or Performance improvent tip.

We have following parameters set
DB2_PARALLEL_IO=*
MUlti page allocation parameter is yes

Any input ??

1- increase UTIL_HEAP_SZ ten times from default value
2- turn on INTRA_parallel parametes
3- look at load command you can turn off some feature for better performance