ConnectX-8: Qualifying PCIe Extension and Partner Cooling

Distinguish the primary card variants

The C8180 ST0 and DT0 variants share an HHHL format and single OSFP cage, while their extension options differ. ST0 lists Socket Direct; DT0 lists a downstream port. C8180L SL0 is the partner-cooled version. Record this distinction early because it changes PCIe topology, system integration and the thermal design.

Separate InfiniBand and Ethernet configurations

The current ordering table lists 800Gb/s XDR InfiniBand as the default and 2 x 400GbE Ethernet for these C8180 variants. A general 800G label is not enough to choose an Ethernet port configuration. The primary host interface is PCIe 6 x16. Confirm the host capability, software release, port configuration and complete interconnect path rather than interpreting the connector as a throughput guarantee.

Treat partner cooling as a system design

The SL0 cooling guide makes the customer responsible for keeping every board component within its thermal limits. It specifically discusses the thermal transfer plate, PCB and networking cage. In a low-airflow or liquid-cooled environment, components outside the primary cold plate still need cooling. The partner thermal assembly may also exceed nominal PCIe dimensions, so validate real chassis clearance and the whole board, not only the ASIC temperature.

Keep the two accessories distinct

The C8180X kit, 930-9XAX6-0025-000, contains an auxiliary PCIe board and 250 mm MCIO cable. The 930-9XCBL-000A-000 kit is a low-speed debugging extender with a 200 mm 30-pin IPEX cable and provides access to PPS and management signals. They solve different integration problems. The C8180X public tables disagree on auxiliary generation and signal rate; request confirmation before promising Gen6 performance through that kit.

Define acceptance tests

Before rollout, verify the actual PCIe negotiated state, intended network mode, qualified cable or transceiver, thermal behavior under the representative workload, firmware identity and recovery procedure. Keep reference specifications and measured acceptance results as separate records.

Independent technical selection guidance. No claim of a SwitchInfra installation, supplied batch, certified performance or customer outcome.

Public references

• NVIDIA ConnectX-8 SuperNIC User Manual | NVIDIA ConnectX-8 SuperNIC User Manual
• Specifications | NVIDIA ConnectX-8 SuperNIC User Manual
• Supported Interfaces | NVIDIA ConnectX-8 SuperNIC User Manual
• General Cooling Recommendations for Partner-Cooled SuperNICs | NVIDIA ConnectX-8 SuperNIC User Manual
• PCIe Auxiliary Card Kit | NVIDIA ConnectX-8 SuperNIC User Manual
• PCIe Auxiliary Kit Technical Specifications | NVIDIA ConnectX-8 SuperNIC User Manual