Zeebe not able to process instances

Hi Camunda team,
My camunda engine is not able to process instances quickly…it is taking time too much time to process instances.

these are my configuration:
Zeebe broker: 11 borker, 4gb ram and 2 cpu per broker
zeebe gateway: 3 gateway
elasticsearch: 4 data node and 1 master node (each having 6gb ram)
java client: 4 pods with 4gb each…

i started 5000 instances in 30min and still it is taking time to process. (more than 2 hour)
Average memory usage of zeebe broker and java client is much less than what is given…around 2gb average for both zeebe and java client application.

i have total of 2 job worker and worker.threads=10
worker.maxJobActive=32 and job.pollInterval=PT0.1S

do i need to add anything or make any changes?