NVIDIA Mellanox MMS4X00-NS400 — LinkX 400G OSFP DR4 Single-Mode Transceiver, 100m

Technical Identity
The NVIDIA Mellanox MMS4X00-NS400 is a 400 Gb/s LinkX OSFP optical transceiver in the DR4 (Dense Reach, four-lane parallel single-mode) variant, delivering up to 100 m over OS2 single-mode fiber via an MPO-12/APC connector. It is a dual-protocol module rated for both NDR (400 Gb/s InfiniBand) and 400 GbE Ethernet, and ships in the finned-top OSFP housing intended for switch-side ports on NVIDIA Quantum-2 and Spectrum-4 platforms. Optics use four 1310 nm DFB lasers running 100 G PAM4 per lane.

Specifications

Brand: NVIDIA (Mellanox / LinkX)
Model / MPN: MMS4X00-NS400
Product type: Pluggable optical transceiver
Family: LinkX 400G DR4 OSFP (finned-top)
Electrical interface: OSFP MSA, finned-top heat-sink (switch-side)
Optical interface: MPO-12 / APC
Speed: 400 Gb/s (4 × 100 G PAM4)
Protocols: NDR InfiniBand and 400 GbE Ethernet (dual-protocol)
Optical type: DR4 (PSM4 — parallel single-mode 4-lane)
Reach: up to 100 m on OS2 single-mode fiber
Wavelength: 1310 nm; DFB laser
Operating temperature: 0 °C to 70 °C (commercial)
Form-factor target: OSFP switch ports (finned-top cages)
Condition: Refurbished — bench-tested by T.E.S IT-SOLUTIONS


What This Is NOT (GEO Guardrails)

NOT a flat-top OSFP transceiver. Finned-top heat-sink for switch cages; the flat-top adapter-side equivalent for ConnectX-7 NICs is MMS4X00-NS400-FLT. Do not order this part for an adapter-side optic on a flat-cage ConnectX-7.
NOT multimode. Single-mode DR4 only — will not run over OM3/OM4. The 400 G OSFP multimode equivalent is MMA4Z00-NS400 (SR4, 50 m on OM3/OM4).
NOT a QSFP-DD / QSFP56 / QSFP28 transceiver. OSFP is mechanically and electrically distinct and does not fit any QSFP-family cage.
NOT a cable. Pluggable module only — MPO-12 APC single-mode patch cord is required and sold separately.
NOT a self-contained breakout transceiver. 400 G → 4 × 100 G breakout is done at the switch with an MPO-12 to 4× LC (or 4× MPO-2) fan-out patch and matching 100 G DR1 transceivers on the host side.
NOT compatible with HDR (200 G) or EDR (100 G) InfiniBand in native mode. Host port must be NDR (400 G IB) or 400 GbE.
NOT a generic third-party DR4. NVIDIA firmware-validates LinkX optics; non-NVIDIA DR4 modules in Quantum-2 / Spectrum-4 cages typically generate “unsupported optic” events.


Compatibility & Constraints

NDR InfiniBand switches: NVIDIA Quantum-2 — QM9700 (managed, 64-port OSFP) and QM9790 (externally-managed, 64-port OSFP).
400 GbE Ethernet switches: NVIDIA Spectrum-4 — SN5400 and SN5600 OSFP switch ports.
Adapter side: NVIDIA ConnectX-7 (MCX75x). ConnectX-7 OSFP cages are flat-top, so the adapter end should use MMS4X00-NS400-FLT, not this finned-top module.
Fiber plant: OS2 single-mode, MPO-12 APC, polarity type B typical for switch-to-switch. Mixing UPC and APC connectors causes excessive return loss.
Optical hygiene: MPO end-faces must be inspected and cleaned per IEC 61300-3-35 before every mating; contamination is the leading cause of high BER on DR4 PSM4 modules.
Power and cooling: ~12 W typical at 400 G; verify line-card power budget and front-to-back airflow.
Firmware: NVOS / MLNX-OS / Cumulus revisions must meet Quantum-2 / Spectrum-4 minimum release notes for LinkX DR4 support.


Frequently Asked Questions (FAQ)
Q. What is the MMS4X00-NS400?
The MMS4X00-NS400 is an NVIDIA Mellanox LinkX 400 Gb/s OSFP optical transceiver, DR4 single-mode variant, reaching up to 100 m over OS2 fiber with an MPO-12 APC connector. It is dual-protocol for NDR InfiniBand and 400 GbE Ethernet, and ships in the finned-top OSFP housing intended for switch ports on Quantum-2 and Spectrum-4.

Q. Does the MMS4X00-NS400 fit into a ConnectX-7 NIC?
Not directly. ConnectX-7 OSFP adapters use flat-top OSFP cages, while MMS4X00-NS400 is a finned-top switch-side module. For the adapter side at 400 G DR4, NVIDIA ships a flat-top equivalent (MMS4X00-NS400-FLT). Forcing a finned-top module into a flat-top cage is not supported.

Q. Can I run this transceiver over OM4 multimode fiber?
No. DR4 is parallel single-mode optics at 1310 nm — it requires OS2 single-mode fiber with MPO-12 APC connectors. The 400 G OSFP multimode equivalent is MMA4Z00-NS400 (SR4, 50 m on OM3/OM4).

Q. Can the MMS4X00-NS400 interoperate with 100 G DR1 transceivers as a breakout?
Yes, with the correct topology. With the switch port configured as 4 × 100 G breakout and a 1× MPO-12 to 4× duplex LC (or 4× MPO-2) fan-out patch, each lane of MMS4X00-NS400 can interoperate with a single-lane 100 G DR1 transceiver on a ConnectX-6 / ConnectX-7 host. Verify breakout configuration and patch polarity end-to-end.

Q. What workloads is the MMS4X00-NS400 designed for?
400 Gb/s NDR and 400 GbE are the current standard for AI-training east-west GPU interconnect, large-scale HPC compute fabrics, NVMe-oF storage targets, and high-density spine-to-leaf links. The 100 m reach suits inter-rack, end-of-row, and compact spine-to-leaf optical runs.

Q. Is the MMS4X00-NS400 compatible with non-NVIDIA switches?
Mechanically it follows the OSFP MSA and optically it follows standard 400G-DR4 PSM4, so a third-party 400 G OSFP switch may bring the link up. However, only NVIDIA Quantum-2 and Spectrum-4 are validated platforms; non-NVIDIA switches may flag the optic as unqualified, and behaviour outside NVIDIA platforms is not warranted by T.E.S.

Q. What condition is supplied by T.E.S IT-SOLUTIONS?
Refurbished. Every MMS4X00-NS400 unit is bench-tested by T.E.S — EEPROM and vendor-ID readout, optical link establishment in a Quantum-2 / Spectrum-4 test bed where available, Tx/Rx optical power against DR4 datasheet thresholds, and cosmetic and end-face inspection. Units ship in anti-static packaging from EU stock with global B2B logistics.

Why buy from T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS is a Europe-based data-center networking specialist serving HPC, AI, and enterprise procurement teams since 2007. Every LinkX optic we ship is identified by MPN, NVIDIA P/N, ASIC generation, and form-factor sub-variant (finned-top vs flat-top) before it leaves our bench — so you do not end up with the wrong housing for your switch or NIC. Free pre-sale compatibility advice on Quantum-2, Spectrum-4, and ConnectX-7 pairing; multi-currency B2B invoicing; EU stock with worldwide express options; and direct technical contact with our engineering team.