ConnectX-8 XDR to QM9700 Connectivity

Infrastructure & Networking Adapters and Cables InfiniBand/VPI Adapter Cards
1

When connecting a CX-8 SuperNIC 800G XDR 1Port (P/N: 900-9X81E-00EX-ST0) to a QM9700 switch,

is the following connection possible?

CX-8 SuperNIC + MMS4A20-XM800 (transceiver) <----------Cable-------------> (MMS4X00-NS) QM9700

This is intended for 400G NDR communication.

Or should we instead use the MMA4Z00-NS400 transceiver for the CX-8 SuperNIC?

2

Hi @mangooo ,

ConnectX-8 is planarized, hence NDR is not supported.

Thanks,

Chen

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3

For 400G NDR connectivity between a CX-8 SuperNIC (800G XDR, 1-port) and a QM9700 switch:

No — MMS4A20-XM800 should not be used in this scenario.

MMS4A20-XM800 is an 800G XDR InfiniBand transceiver, intended for XDR-rate links. It is not supported to down-negotiate to 400G NDR when connected to a QM9700.

For a supported and interoperable setup, you should use a 400G NDR-rated OSFP module on the CX-8 side, such as MMA4Z00-NS400, paired with MMS4X00-NS400 on the QM9700.

In short:

CX-8 + QM9700 @ 400G NDR → use 400G NDR optics
800G XDR optics are only for XDR-capable links and switches

This aligns with NVIDIA’s supported optics and InfiniBand link-rate requirements.