we recognize slow speed on an AMD H11SSL-i single socked Boards with the latest Bios 1.0C
Two servers connected over a Mellanox SN2100 switch.MSN2100
Perforamce mode enabled
On this setup, we run an Ubuntu Kernel 4.15.0-37.40,
but we recognize this problem also with the 4.19.1 mainline kernel
and an old ubuntu 4.4 Kernel.
We use to try two different kinds of nic
First the Mellanox MCX556A-ECAT
Second the Mellanox MCX456A-ECAT
The problem is with an iperf3 parallel benchmark test
we only reach 60GBit on the MCX556A-ECAT and 50GBit on the MCX456A-ECAT.
With an Intel Broadwell (SuperMicro X10SRi-F Board), the iperf3 test shows results near 90 GBit what is ok with Spectre and Meltdown mediation.
Has anyone an Idea what could be the reason?
I would like to suggest reviewing the following community page:
Also, would like to suggest using iperf2 instead of iperf3 and use more threads by adding the -P flag.
If the performance will still be lower, please open a case with Mellanox support for further investigation by sending an email to firstname.lastname@example.org.