NVIDIA Mellanox C-DQ8FNM050 400GbE QSFP-DD Active Optical Cable, 50m: This is a 50-meter active optical cable (AOC) engineered for 400Gb/s Ethernet (400GbE) point-to-point connectivity using two QSFP-DD form-factor heads. The cable uses VCSEL-based optics over multi-mode fiber and is a factory-terminated, fixed-length integrated assembly. This is not a transceiver, not a breakout cable, and not a passive copper DAC. This is a refurbished unit.
Engineering Context
The C-DQ8FNM050 targets cross-row and inter-rack 400GbE topologies where passive or active copper cannot reach. At 50 meters it is well above the practical limit of copper DACs and inside the typical reach window for short-wavelength 400G AOCs. The cable carries 8 lanes at 50Gb/s PAM4 to deliver an aggregate 400GbE link, with RS-FEC handled by the host. As an integrated assembly the optical end-faces are sealed at the factory, eliminating the contamination risks that affect transceiver + MPO patch cord deployments. The cable is significantly lighter and thinner than copper at this distance, reducing tray load.
Deployment & Use Cases
400GbE spine-leaf interconnects between racks across a data hall. AI/ML GPU cluster fabric uplinks at 400G. High-density storage backbone connections to modern Ethernet spines. Connecting NVIDIA Spectrum-3 / Spectrum-4 400G switches to ConnectX-7 adapters in 400G fabrics.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: C-DQ8FNM050
Form Factor: QSFP-DD to QSFP-DD (Point-to-Point)
Cable Type: Active Optical Cable (AOC), Multi-Mode Fiber
Data Rate: 400GbE (8x 50Gb/s PAM4)
Length: 50m
Protocol: 400GbE Ethernet
Termination: Factory sealed, integrated optics
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Compatible with NVIDIA Spectrum-3 and Spectrum-4 400G Ethernet switches and ConnectX-7 400G EN adapters with QSFP-DD ports configured for 400GbE PAM4. Not compatible with QSFP56, QSFP28, or OSFP ports. Not validated for InfiniBand NDR ports — those use OSFP and a different signaling profile. Does not support 2x200G or 4x100G breakout out of the box; breakout requires a different cable model. Fixed 50m length, non-detachable.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS tests every 400G AOC for optical power per lane, lane integrity, and connector mating before shipment. Visit tes-itsolutions.com for expert consultation on 400GbE fabric design, global shipping, and a 1–3 day handling window.