High Network Perfomance

Hi Guys,

I'm trying tunning a FreeBSD 8.2 to high perfomance network with pf. My
server configuration is:

Dell 1950
CPU: Intel(R) Xeon(R) CPU            5130  _at_ 2.00GHz (1995.03-MHz K8-class
CPU)
4 x CPU
2 NIC (<Broadcom NetXtreme II BCM5708 1000Base-T)
1 NIC (em0: <Intel(R) PRO/1000 Network Connection 7.1.9>)

I want to reach the high processing of packets per second and use pf as
synproxy and we still processor to handle others packets or flows.

I know that em drivers has MULTI_QUEUE implementation that helps high
performance for Intel drivers, but I couldn't see more information about. We
can reached 500k pps, but no more traffic was processed by this interface.

I've already enabled net.isr.direct but with Intel Drivers does not work and
the most processors are in System instead of Interrupts, why? When I enable
net.isr.direct the processing is balanced for on CPU in system and another
in interrupt and I reached 1M pps, but the total perfomance is down, the
load grow up too fast.

I've changed some parameter in sysctl for intel drivers, but it doesn't have
effect.

Someone know what I can do to reach more packets performance? I want to use
this FreeBSD as a router/firewall only.

Thanks,
Victor