Slow Browser-Game, Solution?

[lepima]

Hi,

have some problems with an Online-Browser-Game:

Hardware of the Webserver:

P4 3,2 Ghz
3 GB RAM
Apache2, PHP4

httpd.conf:
<IfModule prefork.c>
StartServers 10
MinSpareServers 20
MaxSpareServers 30
MaxClients 256
ServerLimit 1024
MaxRequestsPerChild 1000
</IfModule>

eaccelerator installed

Hardware of the DB-Server

DualXeon 3.0
2 GB RAM
mySQL 4.21

my.cnf:

set-variable = key_buffer=1536
set-variable = max_allowed_packet=8M
set-variable = table_cache=512
set-variable = sort_buffer_size=16M
set-variable = read_buffer_size=32M
#set-variable = sort_buffer=2M
#set-variable = record_buffer=4M
set-variable = thread_cache=8
#set-variable = query_cache_size=32M
set-variable = thread_concurrency=2
set-variable = max_connections=1500
set-variable = thread_stack=512K
set-variable= myisam_sort_buffer_size=128M

set-variable = innodb_buffer_pool_size=1024M
set-variable = innodb_additional_mem_pool_size=4M
innodb_data_home_dir = /var/lib/mysql/
innodb_log_arch_dir = /var/lib/mysql/
innodb_log_group_home_dir = /var/lib/mysql/
innodb_data_file_path = ibdata1:64M:autoextend:max:512M
# we keep this at around 25% of of innodb_buffer_pool_size
# sensible values range from 1MB to (1/innodb_log_files_in_group*innodb_buffer_pool_size)
set-variable = innodb_log_file_size=8M
# this is the default, increase if you have very large transactions.
set-variable = innodb_log_buffer_size=32M
# this is the default, and won't hurt you.
# you shouldn't need to tweak it.
set-variable = innodb_log_files_in_group=2
# see the innodb config docs, the other options are not always safe
innodb_flush_log_at_trx_commit=1

The Problem:

With more than 400 connections the (In-)game and Website is real slow. Maybe I did the wrong "tuning"
Top on BOTH machines is under 40%.

Network:
SWITCH -> WEB (2 NICS)-> DB (1NIC)

Any Ideas how to increase more performance?

lepima