[SR-Users] low performance with udp_children and async_workers

Hello, Based on business requirements, 35% of invites should be handled by async_workers and 65% with be handled by main children. The target is 1500cps. I'm using the following conf : children=64 async_worker=128 when doing performance tests using SIPp, I figured out the 1500cps is well supported by the conf above, but when I updated the data in database to not use anymore async workers, the cps is getting decreased and it was between 200 and 500. This a client requirements is to be able to enable/disable feature that needs to be handled by async workers. Could you please help me on this? Thanks in advance