Basic tuning hints

Increase the default IP port range available for outgoing connections
echo "1024 49151" > /proc/sys/net/ipv4/ip_local_port_range

Ramp up the TCP backlog to deal with larger numbers of connections
echo "256" > /proc/sys/net/ipv4/tcp_max_syn_backlog

Ramp up the max file count
echo "16384" > /proc/sys/fs/file-max

Make sure that you're using DMA on your disk IO
Even on your IDE root/log disks