Start Process Smart service is taking huge time for 500 occurrence and running in Loop

I am using Smart process smart service which is used to do load balancing and executing in Loop. Variable contains 500 rows

As of now it is taking 40-50 min which is very high even loop number is not much. Is there any way we can optimize it further.

We are passing few parameters into called process but as Start process smart service is asynchronous, so performance is not having any dependency on called process. 

Appreciate any quick suggestions.