Disproportionate resource utilization (cpu) in a multi-search-node cluster with non-default(>6) index partitions and index replicas

Observing disproportionate cpu utilization in a multi-search-node cluster with non-default(>6) index partitions and index replicas 

Test/Cluster setup  

• Nodes : 10
• KV/Search : 5:5
• Total docs : 20 M
• num of search Index : 1
• num of fields : 6
• Index Partition : 16
• index replica : 1
• workers : 20
• queryType : 1_conjuncts_2_disjuncts
• number_cores; 16