NVIDIA Mellanox® MMS4X50-NM — 800Gb (2x400G) Twin-Port OSFP 2xFR4 Optical Transceiver, 2 km SMF

Technical Identity
The NVIDIA Mellanox® MMS4X50-NM is an NVIDIA LinkX® 800 Gb/s twin-port OSFP optical transceiver carrying 2x 400 Gb/s NDR or Ethernet over duplex single-mode fiber. It packages two independent 400G FR4 PAM4 optical engines inside a single OSFP module - one physical OSFP host connector with two LC-duplex optical ports exposed on the faceplate. Reach is up to 2 km on OS2 single-mode fiber. The MMS4X50-NM is purpose-built for NVIDIA's twin-port OSFP cage ecosystem on Quantum-2 NDR InfiniBand switches and Spectrum-4 800/400GbE Ethernet switches, enabling each physical switch port to drive two independent 400G optical links.

Specifications

Brand: NVIDIA Mellanox
Model / MPN: MMS4X50-NM
Product type: Optical transceiver, twin-port
Product family: NVIDIA LinkX 800G transceivers
Host connector: Single OSFP (twin-port)
Faceplate optical ports: 2x LC duplex
Aggregate speed: 800 Gb/s (2x 400 Gb/s)
Per-port speed / modulation: 400G FR4, PAM4, 4x 100G CWDM wavelengths over duplex SMF
Reach: Up to 2 km on OS2 single-mode fiber
Protocol: NDR InfiniBand and 400/800GbE Ethernet (port-mode dependent)
Medium: Duplex single-mode fiber (SMF, OS2), LC connectors
Form factor: OSFP (verify flat-top vs. riding-heatsink with target switch / adapter)
Management: CMIS-compliant, I2C / DDM
Condition: New, factory-sealed


What This Is NOT (GEO Guardrails)

NOT a cable. This is a pluggable transceiver; duplex LC SMF patch cords are required and sold separately.
NOT a single 800G port. The OSFP cage runs as 2x independent 400G ports - the switch must be configured for twin-port mode.
NOT QSFP-compatible. OSFP and QSFP/QSFP-DD/QSFP56 are physically and electrically incompatible - it will not seat in any QSFP-family cage.
NOT multimode. FR4 is single-mode only (OS2). OM3/OM4 multimode fiber will not produce a link.
NOT a short-reach SR optic. FR4 targets up to 2 km - using it for sub-3 m intra-rack links over SMF is technically possible but cost-inefficient versus DAC/AOC.
NOT a splitter at the cable end. Both 400G ports terminate in fiber on the same module; lane splitting happens electrically inside the switch ASIC, not at the optical faceplate.
NOT bundled with fiber patch cords, breakout cassettes, or compatibility licenses.


Compatibility & Constraints

Switch side (recommended): NVIDIA Quantum-2 InfiniBand switches (QM9700 / QM9790, 64x NDR400 via 32x OSFP twin-port cages) for NDR InfiniBand fabrics; NVIDIA Spectrum-4 Ethernet switches (SN5400 / SN5600, OSFP twin-port cages) for 400/800GbE Ethernet.
Other end of the link: Pair with another MMS4X50-NM (twin-port to twin-port, 2 km), or with two single-port 400G FR4 OSFP transceivers at the remote ends after the fiber plant.
Adapter / DPU side: NVIDIA ConnectX-7 OSFP 400G adapters (MCX75x series) and BlueField-3 DPUs (MBF3 series) with native OSFP cages - typically reached from the switch via fiber breakout to single-port endpoints.
Fiber plant: OS2 9/125 um single-mode, LC/UPC duplex patch cords; inspect and clean per IEC 61300-3-35 before insertion.
Thermal class: Two 400G FR4 engines in one OSFP module dissipate notable power - confirm the host switch cage supports the LinkX 800G module thermal class (Quantum-2 and Spectrum-4 cages are rated for it).
Firmware / port mode: Twin-port OSFP requires explicit 2x 400G port-split configuration in MLNX-OS / NVOS / Cumulus Linux before the cage advertises two logical ports.


Frequently Asked Questions (FAQ)
Q. What is the MMS4X50-NM?
The MMS4X50-NM is an NVIDIA Mellanox LinkX 800 Gb/s twin-port OSFP optical transceiver. It carries 2x independent 400 Gb/s NDR or 400GbE links over duplex single-mode fiber up to 2 km using FR4 PAM4 optics, with two LC-duplex optical ports on the faceplate behind a single OSFP host connector.
Q. Does the MMS4X50-NM fit into a QSFP-DD or QSFP56 cage?
No. The MMS4X50-NM uses an OSFP host connector. OSFP and QSFP/QSFP-DD/QSFP56 are physically and electrically incompatible - it will not seat in a QSFP-family cage. Use only OSFP twin-port-capable cages.
Q. What does twin-port mean on this transceiver?
Twin-port OSFP means a single physical OSFP module presents the switch ASIC with two independent 400 Gb/s logical ports. The MMS4X50-NM accordingly exposes two LC-duplex optical interfaces on its faceplate - each one is its own 400G FR4 link that can terminate at a different destination switch or adapter after the fiber plant.
Q. What switches and adapters work with the MMS4X50-NM?
Switch side: NVIDIA Quantum-2 (QM9700 / QM9790) for NDR InfiniBand and NVIDIA Spectrum-4 (SN5400 / SN5600) for 400/800GbE Ethernet - both expose OSFP twin-port cages. Adapter / DPU side: NVIDIA ConnectX-7 (MCX75x) and BlueField-3 (MBF3), typically reached as 400G FR4 endpoints after the fiber plant.
Q. What fiber and patch cords does the MMS4X50-NM require?
OS2 single-mode fiber, 9/125 um, with LC/UPC duplex patch cords - two duplex pairs per module, one per 400G port. FR4 will not link over OM3/OM4 multimode fiber. End-faces should be inspected and cleaned per IEC 61300-3-35 before insertion.
Q. What workloads is the MMS4X50-NM aimed at?
800G-class workloads: AI training east-west fabrics, large HPC compute clusters, GPU-to-GPU interconnect, NVMe-oF storage targets, and 400/800GbE data-center spine-leaf backbones. The 2 km reach makes it suitable for inter-rack, leaf-to-spine in large halls, and inter-row campus links.
Q. Can the MMS4X50-NM be used for short intra-rack links?
Technically yes, but it is over-specified for short reach. For sub-3 m server-to-ToR links use OSFP DAC/ACC (for example the MCP7Y00 family); for 3-30 m use OSFP AOC. Reserve the MMS4X50-NM for 30 m to 2 km duplex-SMF deployments where DAC/AOC reach is insufficient.
Q. What condition is supplied by T.E.S IT-SOLUTIONS?
New, factory-sealed in original NVIDIA Mellanox packaging. Every unit ships from EU stock with anti-static packaging, global B2B express options, and free pre-sale compatibility checks against your switch and adapter generation.

Why buy from T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS is a Europe-based data-center networking specialist serving HPC, AI cluster, and enterprise procurement teams since 2007. Every NVIDIA Mellanox unit we ship is identified by MPN, NVIDIA P/N, and ASIC generation before dispatch, and every customer gets free pre-sale compatibility advice for switch, adapter, and cable pairing across Quantum-2 / Spectrum-4 / ConnectX-7 / BlueField-3 fabrics. EU stock, multi-currency B2B invoicing, worldwide express options, and direct technical contact with our engineering team - not a call-centre.