NVIDIA Mellanox C-DQ8FNM020 400GbE QSFP-DD to QSFP-DD Active Optical Cable, 20m OM3: This is a 20-meter Active Optical Cable (AOC) with QSFP-DD connectors on both ends, engineered for 400Gb/s Ethernet point-to-point interconnects (NVIDIA P/N 980-9I08R-00W020). The cable uses 8 lanes of 50Gb/s PAM4 over OM3 multi-mode fiber. This is a fixed-length integrated assembly, not separate transceivers with a detachable patch cord, and not a passive copper DAC. This is a refurbished unit.
Engineering Context
The C-DQ8FNM020 implements 400GBASE-SR8 signaling per IEEE 802.3cd using 8x50Gb/s PAM4 lanes. At 20 meters, it bridges row-to-row Ethernet links where passive copper cannot reach and where an installed transceiver-plus-MPO solution would be costly to terminate. The factory-terminated AOC eliminates fiber-end-face contamination risk during installation. The OM3 jacket and integrated optics deliver complete EMI immunity and lower bend-radius stress than copper bundles.
Deployment & Use Cases
Spine-leaf 400GbE fabrics in modern data halls. AI and HPC clusters connecting GPU compute racks to storage spines over distances exceeding passive copper reach. Hyperscale aggregation links between Top-of-Rack and End-of-Row Spectrum-3 or Spectrum-4 switches. Cloud network fabrics where 50Gb/s PAM4 lane structure is required end-to-end.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: C-DQ8FNM020
NVIDIA P/N: 980-9I08R-00W020
Form Factor: QSFP-DD to QSFP-DD (Point-to-Point)
Data Rate: 400GbE (8x50Gb/s PAM4)
Length: 20m
Fiber Type: OM3 Multi-Mode
Standard: IEEE 802.3cd 400GBASE-SR8
Cable Type: Active Optical Cable (AOC)
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Designed for use with NVIDIA Spectrum-3 (SN4000) and Spectrum-4 (SN5000) switches, and ConnectX-6/7 adapters configured for 400GbE QSFP-DD. Requires both endpoints to negotiate 8x50G PAM4; will not interoperate with QSFP56 200GbE ports without a breakout assembly. This is a fixed 20m direct AOC and does not support 2x200G or 8x50G electrical breakout. Not compatible with InfiniBand HDR/NDR ports. The cable is QSFP-DD only and does not fit QSFP56 or QSFP28 cages.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS validates each AOC for optical power, lane integrity, and connector condition prior to shipment. Visit tes-itsolutions.com for global shipping with 1–3 day handling and expert support on 400GbE fabric cabling.