Slow Running of jobs on OPENPBS

Job is running fine on 1 node with 48 cores but gets slow for the 2 nodes with 48 cores.
I need help to resolve this issue.

Please check whether it is running slow without using openPBS on 2 nodes.
Also, it should not be related to openPBS, once the job gets scheduled on to the node(s) then rest is related to the performance of the application on that respective hardware (node) in that environment.

Thanks Adarsh,
Will look into it.