NVIDIA Mellanox C-DQ8FNM003 400GbE QSFP-DD AOC 3m: The NVIDIA Mellanox C-DQ8FNM003 is a 3-meter active optical cable (AOC) with QSFP-DD connectors on both ends, engineered for 400GbE point-to-point interconnect. Each end uses 8 lanes of 50Gb/s PAM4 to deliver 400Gb/s per cable. This is a fixed-length integrated AOC assembly — not a transceiver pair with detachable patch fiber, and not a copper DAC. This is a refurbished unit.
Engineering Context
The cable carries 8 × 50Gb/s PAM4 lanes per direction, summing to 400Gb/s aggregate, aligned with IEEE 802.3bs / 802.3cd 400G specifications. AOCs eliminate the dirty-fiber and connector-cleanliness failure modes of separate transceivers and patch cords because both ends are factory-terminated and burned-in together. At 3m the cable typically routes within a single rack or to an immediately adjacent rack, where copper DAC reach is marginal at 400G. Cable is far lighter and thinner than a 400G copper twinax bundle.
Deployment & Use Cases
400GbE Top-of-Rack to compute node interconnect using QSFP-DD on both NIC and switch. Spine-leaf links inside a single rack for QSFP-DD-equipped Spectrum-3/Spectrum-4 platforms. Storage fabric uplinks where 400G is needed and the run is short. Lab and test environments needing reliable 400G plug-and-play without optical patch panels.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number / MPN: C-DQ8FNM003 (NVIDIA PN 980-9I08L-00W003)
Form Factor: QSFP-DD to QSFP-DD
Cable Type: Active Optical Cable (AOC)
Aggregate Data Rate: 400Gb/s
Lane Configuration: 8 × 50Gb/s PAM4
Length: 3 m
Standards: IEEE 802.3bs / 802.3cd 400G
Termination: Factory-terminated, integrated assembly
Breakout: Not a breakout cable — direct 400G end-to-end
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Constraints
Designed for QSFP-DD ports on NVIDIA Spectrum-3 (SN4000) switches and ConnectX-7 400G adapters. Compatible with other vendors' QSFP-DD 400G-DR8 / SR8 host ports that follow the standard 8× 50G PAM4 lane mapping. Not compatible with QSFP56 200G ports (different lane structure) and not compatible with OSFP form factor without an OSFP↔QSFP-DD adapter. This is not a breakout cable — it is direct 400G QSFP-DD to QSFP-DD. Fixed 3 m length.
Why TES
T.E.S IT-SOLUTIONS tests every 400G AOC for per-lane optical power, end-to-end link training, and connector condition before shipment. Visit tes-itsolutions.com for compatibility questions and global shipping. Standard handling time is 1–3 business days.