pgsql-performance issue

Dear Sir/Mam,

I have a PostgreSQL 9.5 instance running on Windows 8 machine with 4GB
of RAM.This server is mainly used for inserting/updating large amounts
of data via copy/insert/update commands, and seldom for running select
queries.

Here are the relevant configuration parameters I changed:

max_connections = 100
shared_buffers = 512MB
effective_cache_size = 3GB
work_mem = 12233kB
maintenance_work_mem = 256MB
min_wal_size = 1GB max_wal_size = 2GB
checkpoint_completion_target = 0.7
wal_buffers = 16MB
default_statistics_target = 100

After setting in postgresql.conf. I run the select query to fetch large
amount of record of 29000 in postgresql but it takes 10.3 seconds but
the same query takes 2 seconds for execution in MSSQL.

So my query is how to improve the perfermance in postgresql.

Regards,
Debasis Moharana
.NET Software Developer