[Devil-Linux-discuss] Bad routing performance - only app. 100MBit/s

[<udo...@al...>]

Hi,
I have an strange issue on a devil-linux-box with 5 gigabit-nics.
 From each network I got an normal performance to/from the firewall:
iperf shows 781 Mbits/sec

a little bit less to the firewall nic from the other lan:
iperf -c 192.168.225.254
775 Mbits/sec

But to an host inside the other lan the performance drop:
iperf -c 192.168.225.2
94.3 Mbits/sec

The network connection or the host seems be ok, because from the 
firewall I got normal values (it's an VM):
iperf -c 192.168.225.2
643 Mbits/sec
725 Mbits/sec - to an physical host

The big question: why I'm not able to reach this speed through the 
firewall??

The firewall has an 4 core i5 CPU M 520 @ 2.40GHz

and the NICs are:
01:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network 
Connection
02:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network 
Connection
03:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network 
Connection
04:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network 
Connection
05:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network 
Connection

Devil-Linux 1.6.3-i686

Are there any trick to use only one core for iptables/routing???


Any ideas??

Best regards

Udo