slow loop inserts?

Hi, I'm new to postgres and I have the next question.

I have a
php program that makes 100000 inserts in my database.
autoincrement
numbers inserted into a table with 5 columns.
The script takes about 4
minutes from a webserver
Is it a normal time?

How could reduce this
time by a bulce of inserts?

When I turn off fsync get much more
performance, but it is not ideal in power failure

HARDWARE: 2 disks
1TB 7200 rpm with software raid 1 (gmirror raid)

8 Gb RAM

CPU Intel
Quad Core 2.4 Ghz

OS: Freebsd 8.2

POSTGRES VERSION: 9.0.4

MY
POSTGRES CONFIG:

listen_addresses = '*'
wal_level = archive
fsync =
on
archive_mode = on
archive_command = 'exit 0'
maintenance_work_mem
= 480MB
checkpoint_completion_target = 0.5
effective_cache_size =
5632MB
work_mem = 40MB
wal_buffers = 16MB
checkpoint_segments = 30

shared_buffers = 1920MB
max_connections = 40

MY EXECUTION TIME OF MY
SCRIPT:

[root(at)webserver ~]# time php script.php

real 4m54.846s
user
0m2.695s
sys 0m1.775s

MY SCIPT: