[dpdk-dev] Performance hit - NICs on different CPU sockets

[Take Ceara]

Hi,

I'm reposting here as I didn't get any answers on the dpdk-users mailing list.

We're working on a stateful traffic generator (www.warp17.net) using
DPDK and we would like to control two XL710 NICs (one on each socket)
to maximize CPU usage. It looks that we run into the following
limitation:

http://dpdk.org/doc/guides/linux_gsg/nic_perf_intel_platform.html
section 7.2, point 3

We completely split memory/cpu/NICs across the two sockets. However,
the performance with a single CPU and both NICs on the same socket is
better.
Why do all the NICs have to be on the same socket, is there a
driver/hw limitation?

Thanks,
Dumitru Ceara