PSQL performance - TPS

Hello,

We are working on development of an application with postgresql 9.6 as
backend. Application as a whole is expected to give an throughput of 100k
transactions per sec. The transactions are received by DB from component
firing DMLs in ad-hoc fashion i.e. the commits are fired after random
numbers of transaction like 2,3,4. There is no bulk loading of records. DB
should have HA setup in active passive streaming replication. We are doing
a test setup on a 8-core machine having 16 GB RAM. Actual HW will be
better.

Need help in:
1. On this env(8core cpu, 16GB) what is the TPS that we can expect? We have
tested with a simple Java code firing insert and commit in a loop on a
simple table with one column. We get 1200 rows per sec. If we increase
threads RPS decrease.

2. We have tuned some DB params like shared_buffers, sync_commit off, are
there any other pointers to tune DB params?

Thanks.