Can NVIDIA ConnectX-7 (MCX755106AC-HEAT) Support 100G x1 (Single-Lane 100G)?

Infrastructure & Networking Adapters and Cables Ethernet Adapter Cards
1

I am using ConnectX-7 (P/N: MCX755106AC-HEAT). It is a dual QSFP port NIC. I have connected QSFP112G-400G cable to it and trying to bring-up 100G x1 link.
But I am unable to do so. I can see in ethtool utility that, ConnectX-7 do supports,

  • 100000baseKR/Full
  • 100000baseSR/Full
  • 100000baseLR_ER_FR/Full
  • 100000baseCR/Full
  • 100000baseDR/Full
  1. Does this supports 100G x1 config ?
  2. If Yes, Please let me know why 100G x1 link is not happening with connectX-7 NIC ?

Please let me know if I am missing anything here.

2

Hi amarnathpujari18,

First of all, yes, our CX7 (MCX755106AC-HEAT) Supports 100G speed.
But at this moment, I am not sure your QSFP112 cable capability.

  1. Please check the “Supported Cable Speed” from the “# mlxlink -d xx:xx.x -m” command output.
    Note: xx:xx.x is the bdf of this CX7 NIC corresponding PF port, our you can use the mst device name “/dev/mst/mt4129_pciconfX” instead.

  2. If your cable support 100G speed, and your switch up-layer port supports 100G as well, and with Auto Negotiation, then you can use the following commands to try to set the speed to 100G.
    mlxlink -d xx:xx.x -s 100G --link_mode_force
    mlxlink -d xx:xx.x
    mlxlink -d xx:xx.x -a tg
    mlxlink -d xx:xx.x

Thanks!

3

Hi @longranw ,
Thanks for your response.

I would like to know, if the same NIC can support 200G_x2 ?

here, 200G_x2 I am referring to , total bandwidth of 200G achieved over 2 lanes. i.e. 100G per lane and such 2 lanes.

Please let me know if this is possible with the Nvidia CX7 (MCX755106AC-HEAT) NIC ?

Thanks !

4

Yes, MCX755106AC-HEAT supports 100G per lane with 2 lanes.

5

Hi @longranw ,

Thanks for quick response.

I can see for Nvidia NIC below 200G configs are supported,
200000baseKR2/Full
200000baseSR2/Full
200000baseCR2/Full
200000baseLR2_ER2_FR2/Full
200000baseDR2/Full

But, I can see, at this link (Nvidia NIC connectX-7)
Ethernet Protocols supported by the electrical interface: (200GAUI-2 C2M, 200GAUI-4 C2M, 200GBASE-CR4)

image
image1469×185 15.3 KB

Here I see, 200GBASE-CR2 is not present.

FYR, I am using 400G QSFP-112G DAC cable for connection. My cable supports 200G_x2 (100G per lane, 2 lanes) configuration.

Please let me know if we can still achieve 200G_CR2 link with connectX-7 with DAC cable mentioned above.

Thanks,
/Amar

6

Hi amarnathpujari18,

You can find all the supported and verified Module/Cable info in this page, as MCX755106AC-HEAT belongs to the CX7 series.
Validated and Supported Cables and Switches - NVIDIA Docs

If your DAC in the supported list, then it’s supported in each link speed.

7

Each lane of the MCX755106AC-HEAT can run at 100G, with a total of 2 lanes.

8

CX-7 can do single-lane 100G in practice, but it depends on driver/firmware support — switch and optics need to match the lane config too.