Freebsd IP Forwarding performance (question, and some info) [7-stable, current, em, smp]

[Paul]

The higher I set the buffer the worse it is.. 256 and 512 I get about 
50-60k more pps than i do with 2048 or 4096.. You
would think it would be the other way around but obviously there is some 
contention going on. :/
I'm sticking with 512 for now, as it seems to make it worse with 
anything higher.
Keep in mind, i'm using random source ips, random source and destination 
ports.. Although that should have zero impact on the amount of PPS it 
can route but for some reason it seems to.. ? Any ideas on that one?   A 
single stream one source ip/port to one destination ip/port seems to use 
less cpu, although I haven't generated the same pps with that yet.. I am 
going to test it soon

Ingo Flaschberger wrote:
> Dear Paul,
>
>> I tried this.. I put  6-STABLE (6.3), using default driver was slower 
>> than FBSD7
>
> have you set the rx/tx buffers?
>
> /boot/loader.conf
> hw.em.rxd=4096
> hw.em.txd=4096
>
> bye,
>     Ingo
>