Getting a better performance - Mailing list pgsql-admin

Hi guys,

I've got 3 DB servers, running PostgreSQL 9.2.14 with PHP APIs:

1 - Master DB (16 cores, 128 GB RAM, RAID 10)

2 - Slave (warm standby DB - full sized)

3 - Slave (warm standby DB - full sized)

4 - Slave (warm standby DB)

I would like to improve the performance, by slowing the response time (ms) of the DB server. 

But I don't know where to start.

Do you have some tips/how to about how can I get the information that I need?

Thanks