Intel X710 Throughput Only 6 Gbit

[camix]

I bought a couple of Intel X710 NICs on Ebay (Cisco & Lenovo). During my iperf3 testing I’m noticing that I’m maxing out at around 6 Gbit instead of 10 Gbit. I know I can get 10 Gbit transfer because when I switch to the onboard 10 Gbit NIC I get full throughput. Is there something on these cards I need to set to maximize the speed? NVM/Firmware version on cards are 8.5 & 8.6. The transceiver modules I’m testing with are:

SFP-10G-T (FS) - Copper
AXS85-192-M3 (10Gtek) - Fiber

[SUM]   0.00-10.00  sec  7.07 GBytes  6.07 Gbits/sec                  sender
[SUM]   0.00-10.00  sec  7.07 GBytes  6.07 Gbits/sec                  receiver

[Zedicus]

@camix

Intel X710 NICs

what is the card plugged into? is it directly to the CPU? or a chipset PCIE bridge that is physically x16 but electrically x2?

10gb NICs can max out other parts of the system before the card its self.

[camix]

Yup the problem was the PCIe slot. It must’ve only been getting x1 PCIe 3.0 per SFP+ port. I moved the card to another slot and it’s now working as expected and I was able to verify it using the Intel PROSet Adapter Configuration Utility.