User Manual

TRex 98 / 113
1. MLX5 can reach
50MPPS while XL710 is limited to 35MPPS. (With potential future fix it will be
65MPPS)
2. with IMIX you should reach ~90Gb/sec (not 100Gb/sec) with one port (Total bandwidth for both ports is 100Gb/Sec)
3. For Stateless/Stateful 256B profiles, ConnectX-4 uses half of the CPU cycles per packet. ConnectX-4 probably can
handle in a better way chained mbufs (scatter gather).
4. In the average stateful scenario, ConnectX-4 is the same as XL710.
5. For Stateless 64B/IMIX profiles, ConnectX-4 uses 50-90% more CPU cycles per packet (it is actually even more
because there is the TRex scheduler overhead) - it means that in worst case scenario, you will need x2 CPU for the
same total MPPS.
Note
There is a task to automate the production of thess reports
7.8.8 Troubleshooting
• Before running TRex make sure the commands ibv_devinfo and ibdev2netdev present the NICS
• ifconfig should work too, you need to be able to ping from those ports
• run TRex server with -v 7 for example sudo ./t-rex-64 -i -v 7
• In case the link_layer is not set to Ethernet you should run this command
[bash]>sudo mlxconfig -d /dev/mst/mt4115_pciconf0 set LINK_TYPE_P1=2 LINK_TYPE_P2=2
[bash]>sudo mlxconfig -d /dev/mst/mt4115_pciconf1 set LINK_TYPE_P1=2 LINK_TYPE_P2=2
see ConnectX-4 getting Started
• It is possible to change the link speed (e.g. 50Gb/40Gb/25Gb) see change speed
for example to change to 50Gb speed
[bash]>sudo ethtool -s enp135s0f1 speed 50000 autoneg off
• Check how many DRAM channels are installed. Less than 4 will impose latency and performance issue
[bash]>sudo dmidecode -t memory | grep CHANNEL
Bank Locator: NODE 0 CHANNEL 0 DIMM 0
Bank Locator: NODE 0 CHANNEL 0 DIMM 1
Bank Locator: NODE 0 CHANNEL 0 DIMM 2
Bank Locator: NODE 0 CHANNEL 1 DIMM 0
Bank Locator: NODE 0 CHANNEL 1 DIMM 1
Bank Locator: NODE 0 CHANNEL 1 DIMM 2
Bank Locator: NODE 0 CHANNEL 2 DIMM 0
Bank Locator: NODE 0 CHANNEL 2 DIMM 1
Bank Locator: NODE 0 CHANNEL 2 DIMM 2
Bank Locator: NODE 0 CHANNEL 3 DIMM 0
Bank Locator: NODE 0 CHANNEL 3 DIMM 1
Bank Locator: NODE 0 CHANNEL 3 DIMM 2
• I can reach maximum rate of 50Gb/sec