Disappointing packets-per-second performance results on a Dell,PE R530

[Jordan Caraballo]

We recently tested a Dell R530 with a Chelsio T580 card, under FreeBSD 10.3, 11.0, -STABLE and -CURRENT, and Centos 7.

Based on our research, including netmap-fwd and with the routing improvements project (https://wiki.freebsd.org/ProjectsRoutingProposal), 
we hoped for packets-per-second (pps) in the 5+ million range, or even higher.

Based on prior testing (http://marc.info/?t=140604252400002&r=1&w=2), we expected 3-4 Million to be easily obtainable.

Unfortunately, our current results top out at no more than 1.5 M (64 bytes length packets) with FreeBSD, and
surprisingly around 3.2 M (128 bytes length packets) with Centos 7, and we are at a loss as to why.

Server Description:
Dell PowerEdge R530 with 2 Intel(R) Xeon(R) E5­2695 CPU's, 18 cores per
cpu. Equipped with a Chelsio T-580-CR dual port in an 8x slot.

** Can this be a lack in support issue related to the R530's hardware? **

Any help appreciated!