High Network Perfomance

Ian FREISLICH ianf at clue.co.za
Fri Aug 5 12:03:28 UTC 2011

Victor Detoni wrote:
> 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  @ 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.

Benchmarking I did a few years ago showed a strong correlation
between forwarding rate and CPU L1 cache size.  As well as an inverse
relationship to the number of CPUs in the system.  At the time,
some architectures were worse than others.  Intel Pentium4/Xeons
had a halving and AMD Opteron/Athlon had about a 7% reduction in
forwarding rate with SMP compared to UP.

I haven't had the chance to re-run these tests recently.

Set net.inet.ip.fastforwarding=1 and run benchmarks to test your
forwarding rates with different configurations.

See for some results:


Ian Freislich

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