NVIDIA ConnectX-7 Adapter Cards User Manual

Port Splitting Configurations

Note

This section applies to the following OPN only:

MCX715105AS-WEAT: NVIDIA ConnectX-7 HHHL Adapter Card, 400GbE (default mode) / NDR IB, Single-port QSFP112, Port Split Capable, PCIe 5.0 x16 with x16 PCIe extension option, Crypto Disabled, Secure Boot Enabled, Tall bracket

ConnectX-7 SuperNICs offer a variety of network port configurations designed to meet the demands of different environments and deployments. This section outlines the available connectivity options for network ports per product model. While the configurations listed here are not exhaustive, they represent the tested and verified options. Customers seeking to support unlisted configurations should contact NVIDIA Support.

The Port Splitting feature allows a single physical networking module (QSFP112) to be split into multiple network ports. This provides flexibility in optimizing port configurations for various network topology use cases.

Key Features

  • Flexibility and Improved Traffic Segmentation: Port splitting enables network administrators to align device ports with their network infrastructure, enabling traffic segmentation and isolation.

  • Increased Network Efficiency: By optimizing traffic flow and reducing congestion, port splitting improves overall network efficiency. Specific physical ports can be assigned to handle certain traffic types or applications, allowing control and performance tuning.

  • Better Utilization of Resources: Instead of needing separate SuperNICs for each logical connection or network interface, port splitting allows a single physical SuperNIC to handle multiple functions. This reduces hardware costs while maintaining high network flexibility.

Use Cases

  • Load Balancing: Distributing traffic across multiple physical ports can improve network load distribution and balance.

  • Resiliency : Multiple physical ports can be used for redundancy, ensuring stable network connections even if one port encounters an issue.

Each configuration in this section includes a diagram and instructions on splitting the network port using the mlxconfig or the UEFI tools. The UEFI tool configures the device before the operating system is up, while mlxconfig configures the device once the operating system is up. Select the tool based on your preference; the configuration is saved across reboots.

mlxconfig: The mlxconfig tool allows users to change configurations without burning the firmware. The configuration is also kept after reset. By default, mlxconfig shows the configurations that will be loaded in the next boot. For more information and instructions, refer to mlxconfig.

UEFI: PreBoot drivers initialize the adapter device, check the port protocol type – Ethernet or InfiniBand - and bring up the port. Then it connects to a DHCP server to obtain its assigned IP address and network parameters and obtain the source location of the kernel/OS to boot from. The DHCP server instructs the PreBoot drivers to access the kernel/OS through a TFTP server, an iSCSI target, or some other service. For more information and instructions, refer to UEFI.

Warning

Before setting the desired configuration, take note of the following warnings:

  • Any new configuration set by the customer overwrites the previous configuration.

  • Misconfiguration can potentially damage the system.

  • It is recommended to establish out-of-band connectivity to the ConnectX-7 SuperNIC before setting any configuration for the first time. This allows resetting the NVConfig parameters to their default values in case of misconfiguration.

  • When switching from one configuration to another (default or non-default), it is advised to first reset the device to its default configuration. This action deletes all current NVConfig settings. For the reset command and further details, refer to the mlxconfig – Changing Device Configuration Tool.

Note

Reboot or power-cycle the SuperNIC for the new configuration to take effect.

The following table summarizes the available port-splitting configurations.

OPNs

Configuration

Configuration Description

MCX753436MS-HEBB

Configuration #1 (Default)

One Ethernet port supporting 400GbE

Configuration #2

Four Ethernet ports, each supporting 100GbE

The MCX715105AS-WEAT ConnectX-7 SuperNIC, featuring a dual-port QSFP112 module, supports up to 200Gb/s. For the reconfiguration to take effect, please perform power cycle.

Configuration #1 (Default): One Ethernet Port Supporting 400GbE

As the default configuration, the device is configured with one Ethernet port, providing an Ethernet rate of 400Gb/s. The configuration is illustrated in the diagram below.

image-2025-11-17_15-17-58-version-1-modificationdate-1764764801924-api-v2.png

Configuration #2: Four Ethernet Ports, Each Supporting 100GbE

In this configuration, the device can be reconfigured to support four 100GbE Ethernet ports. The configuration is illustrated in the diagram below.

image-2025-11-17_15-18-10-version-1-modificationdate-1764764801596-api-v2.png

To apply this configuration, use the following mlxconfig commands:

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mlxconfig -d <device> set MODULE_SPLIT_M0[0]=1 MODULE_SPLIT_M0[1]=2 MODULE_SPLIT_M0[2]=3 MODULE_SPLIT_M0[3]=4 MODULE_SPLIT_M0[4..15]=FF

© Copyright 2025, NVIDIA. Last updated on Dec 3, 2025