On Mon, Jun 13, 2016 at 04:07:37PM +0200, Take Ceara wrote: > 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? > Hi,
so long as each thread only ever accesses the NIC on it's own local socket, then there is no performance penalty. It's only when a thread on one socket works using a NIC on a remote socket that you start seeing a penalty, with all NIC-core communication having to go across QPI. /Bruce