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

Kip Macy kip.macy at
Tue Jul 8 21:06:19 UTC 2008

On Tue, Jul 8, 2008 at 1:46 PM, Brian McGinty <brian.mcginty at> wrote:
>> I have a pre-production card. With some bug fixes and some tuning of
>> interrupt handling (custom stack - I've been asked to push the changes
>> back in to CVS, I just don't have time right now) an otherwise
>> unoptimized igb can forward 1.04Mpps from one port to another (1.04
>> Mpps in  on igb0 and 1.04 Mpps out on igb1) using 3.5 cores on an 8
>> core system.
> I have a 8 core system running stock Linux that easily does line rate
> (ie, 1.488 Mpps) on 3 (82575) interfaces. Ie, 3 * 1.48 Mpps!

Hi Brian
I very much doubt that this is ceteris paribus. This is 384 random IPs
 -> 384 random IP addresses with a flow lookup for each packet. Also,
I've read through igb on Linux - it has a lot of optimizations that
the FreeBSD driver lacks and I have yet to implement.


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