NVIDIA Mellanox MCA4J80-N022 800G NDR OSFP RHS Active Copper Cable, 2.25m: This is a 2.25-meter Active Copper Cable (ACC) for 800Gb/s NDR Twin-Port InfiniBand links between OSFP RHS (Riding Heat Sink, finned-top) connectors. The cable is a fixed-length straight-through assembly with integrated redrivers in each connector. Twin-Port refers to internal NDR signaling (2x 400Gb/s lanes on a single OSFP module), not a breakout into two separate physical connectors. This is not a passive DAC, not an AOC, and not a breakout cable. This is a new (factory-sealed) unit.
Engineering Context
The MCA4J80-N022 carries 800Gb/s as 8 lanes of 100Gb/s PAM4 within a Twin-Port OSFP module. At 2.25 meters, passive copper cannot reliably maintain NDR PAM4 signal integrity, so internal redrivers re-equalize the signal at each end. The OSFP RHS connector style places the heat sink on the outside of the module (riding on top), which is required for thermal compatibility with NVIDIA Quantum-2 switches. ACC at this length is thinner and more flexible than passive 800G DACs, reducing stress on OSFP cages and improving airflow in dense DGX or HGX racks.
Deployment & Use Cases
NDR InfiniBand spine-to-leaf links between adjacent racks in AI training fabrics. Quantum-2 switch-to-switch interconnects within a single row. ConnectX-7 OSFP NIC to Quantum-2 switch connections of approximately 2 meters. BlueField-3 DPU connectivity in NDR pods.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MCA4J80-N022
Form Factor: OSFP RHS to OSFP RHS (straight-through)
Data Rate: 800Gb/s NDR (Twin-Port, 8x 100Gb/s PAM4)
Cable Type: Active Copper Cable (ACC) with redrivers
Length: 2.25 meters
Connector Style: Riding Heat Sink (finned-top)
Protocol: InfiniBand NDR
Power: Active (host-powered)
Condition: New (factory-sealed)
Compatibility & Hard Constraints
Compatible with NVIDIA Quantum-2 InfiniBand switches QM9700 (modular) and QM9790 (fixed), and with ConnectX-7 OSFP NICs and BlueField-3 OSFP DPUs. Requires OSFP cages that accept the RHS finned-top thermal profile. Not compatible with flat-top OSFP variants used inside ConnectX-7 host adapters where the heat sink is on the host PCB rather than the module — verify cage thermal style before deployment. Not a breakout cable; Twin-Port refers to internal signaling only and does not split into two physical connectors. Fixed 2.25m length.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS sources factory-sealed NDR inventory and provides expert consultation on OSFP RHS thermal compatibility before deployment. See the full catalog at https://www.tes-itsolutions.com. Handling time is 1–3 business days.