Hello! There is problem with latest 3.1-1 and 3.2-1 drivers for ConnectX EN NIC.
After rebooting system speed limiting near 4 Gbit/s and no limit after executing ./install.sh
# uname -a
Linux host-2 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt25-1 (2016-03-06) x86_64 GNU/Linux
Device Type: ConnectX
Part Number: MNPH29B-XTC_A1-A2
Description: MELLANOX HAWK2 2-PORT MODULE-LESS 10GBASE R5 KIT W/TALL BRACKET
PCI Device Name: 06:00.0
Port1 MAC: 0002c90444dc
Port2 MAC: 0002c90444dd
Versions: Current Available
FW 2.9.1000 2.9.1000
Status: Up to date
Who is to blame and what to do?
Looking at the Mellanox OFED 3.2 release notes, it is mentioned in the compatibility matrix that the ConnectX-EN cards is not tested against this driver build. As this is an older generation card I would advise to use a previous driver stack which was verified and tested against your HCA.