Checkpoint_segments optimal value

Hello All
i had a database load issue today and when i was checking logs
i saw this message. I m running postgresql 8.3

db::ts:2014-07-17 09:38:21 PDT::LOG: checkpoints are occurring too
frequently (26 seconds apart)
db::ts:2014-07-17 09:38:21 PDT::HINT: Consider increasing the
configuration parameter "checkpoint_segments".
db::ts:2014-07-17 09:38:21 PDT::LOG: checkpoint starting: xlog

pls suggest the optimal checkpoint_segment value i should set

*My current values are this*

checkpoint_segments = 32 # in logfile segments, min 1, 16MB
each
#checkpoint_timeout = 5min # range 30s-1h
#checkpoint_completion_target = 0.5 # checkpoint target duration, 0.0 -
1.0
#checkpoint_warning = 30s # 0 is off

*Current Memory values*

# - Memory -

effective_cache_size = 8GB

shared_buffers = 1024MB # min 128kB or max_connections*16kB
# (change requires restart)
temp_buffers = 64MB # min 800kB
#max_prepared_transactions = 5 # can be 0 or more
# (change requires restart)

work_mem = 512MB # min 64kB
maintenance_work_mem = 2048MB # min 1MB !!! increased to 1GB
10/1/2010 mrostron (to assist autovacuum workers)
#max_stack_depth = 2MB # min 100kB

# - Free Space Map -

max_fsm_pages = 809600 # min max_fsm_relations*16, 6 bytes
each
# (change requires restart)
synchronous_commit = off

#full_page_writes = on # recover from partial page writes
#wal_buffers = 64kB # min 32kB
# (change requires restart)
#wal_writer_delay = 200ms # 1-10000 milliseconds

#commit_delay = 0 # range 0-100000, in microseconds
#commit_siblings = 5 # range 1-1000