Ideal configuration for postgresql 9.3 config

Hi,

I have POstgresql Server 9.3 setup, below are the Hardware specs

CPU: 16 cores

RAM: 48GB

Disk for Data is at a fiber channel SAN storage.

Below are the config

#########################################
listen_addresses = '*'
max_connections = 1024
shared_buffers = 8000MB
temp_buffers = 8MB
work_mem = 4096MB
maintenance_work_mem = 512MB
checkpoint_segments = 512
checkpoint_completion_target = 0.9
enable_hashjoin = on
enable_indexscan = on
enable_material = on
enable_mergejoin = on
enable_nestloop = off
enable_sort = on
enable_tidscan = on
effective_cache_size = 16000MB
log_destination = 'stderr'
logging_collector = on
log_directory = 'pg_log'
log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log'
log_truncate_on_rotation = on
log_rotation_age = 1440
log_rotation_size = 10000
log_line_prefix = '%t %u %d %h '
log_statement = 'ddl'
autovacuum = off
autovacuum_naptime = 60
autovacuum_vacuum_threshold = 2000
autovacuum_analyze_threshold = 250
autovacuum_vacuum_scale_factor = 0.2
autovacuum_analyze_scale_factor = 0.1
autovacuum_vacuum_cost_delay = -1
autovacuum_vacuum_cost_limit = -1
datestyle = 'iso, mdy'
lc_messages = 'en_US.UTF-8'
lc_monetary = 'en_US.UTF-8'
lc_numeric = 'en_US.UTF-8'
lc_time = 'en_US.UTF-8'
default_text_search_config = 'pg_catalog.english'
max_locks_per_transaction = 96
#####################################################

The config are originally from 9.2, we just copy and paste replacing the default of 9.3. We have based some parameters based on the current specs but still, there might be some changes need to be set. Also the autovacuum for some reason was turned off, is it advisable to turn it off or should this be ideal to be turned on? Hope someone can provide advise on the proper or optimized parameters.

Thanks in advance

Oliver