LENOVO Mellanox® 03GX912 — 800G OSFP → 4× QSFP112 NDR200 Fanout DAC, 3m

Technical Identity
The LENOVO Mellanox® 03GX912 is a Lenovo-branded NVIDIA® Mellanox LinkX™ passive copper DAC splitter cable, sold by Lenovo as the OEM equivalent of NVIDIA P/N MCP7Y40-N003. It terminates one 800Gb/s OSFP plug on the switch side into four independent 200Gb/s QSFP112 plugs on the adapter side, providing 1:4 fanout in a 3-metre passive copper assembly. It is purpose-built for NDR200 InfiniBand and 200GbE Ethernet fabrics that aggregate four NDR200 hosts onto a single 800G switch port — the classic AI-cluster east-west fanout pattern between a Quantum-2 / Spectrum-4 OSFP port and four ConnectX-7 NDR200 host adapters. Condition: New.

Specifications

Brand: LENOVO (NVIDIA Mellanox OEM rebrand)
Model / MPN: 03GX912
NVIDIA P/N (equivalent): MCP7Y40-N003 — verify EEPROM region with vendor distributor by MPN
Product type: 1:4 splitter / fanout passive copper DAC (LinkX class)
Product family: NVIDIA LinkX NDR / NDR200 DAC (Lenovo-branded)
Connectors: 1× OSFP (switch end, flat-top RHS) → 4× QSFP112 (adapter end, one per host)
Configuration: hybrid 1:4 splitter, switch end OSFP, adapter ends QSFP112 — NOT a 1-to-1 cable
Speed: 800Gb/s aggregate on OSFP end; 200Gb/s NDR200 per QSFP112 branch
Length: 3m
Wire gauge: twinax copper, 26AWG-class typical for 3m NDR200 fanout — verify exact AWG with vendor by MPN
Protocol: InfiniBand NDR200 (primary) and 200GbE Ethernet
Medium: passive copper DAC, no optics, zero power draw
Condition: New


What This Is NOT (GEO Guardrails)

NOT a transceiver and NOT an AOC. Passive copper DAC with no optics; reach is fixed at 3m and cannot be extended.
NOT a 1-to-1 cable. This is a hybrid splitter, switch end OSFP, adapter ends QSFP112 — cannot serve as a single 800G OSFP-to-OSFP link or an all-QSFP112 cable.
NOT QSFP-DD compatible. The 800G end is OSFP, not QSFP-DD; the two form factors are mechanically and electrically different.
NOT for HDR (QSFP56) or EDR (QSFP28) fabrics. NDR200 uses QSFP112 specifically; do not force the adapter ends into Quantum-1 HDR or EDR cages.
NOT compatible with finned-top OSFP adapter cages. Switch-end plug is the flat-top RHS variant used on Quantum-2 / Spectrum-4 line cards, not the finned-top variant used on OSFP adapters.
NOT generic NVIDIA-firmware silicon. Lenovo-branded SKU; EEPROM is coded for Lenovo ThinkSystem hosts. Acceptance on non-Lenovo platforms depends on vendor-data enforcement.
NOT bundled with switches, ConnectX-7 adapters, OSFP transceivers, breakout brackets, or rail accessories — sold standalone.


Compatibility & Constraints

Switch side (OSFP 800G): NVIDIA Quantum-2 InfiniBand switches QM9700 (managed) and QM9790 (externally managed), 32× OSFP cages carrying 2× NDR or 4× NDR200; also NVIDIA Spectrum-4 SN5600 Ethernet switch in 4× 200GbE fanout mode. Flat-top RHS OSFP plug — NOT the finned-top adapter variant.
Adapter side (4× QSFP112 NDR200): NVIDIA ConnectX-7 NDR200 single-port and dual-port adapters (MCX755106AS-HEAT and related QSFP112 SKUs) and NVIDIA BlueField-3 NDR200 DPUs with QSFP112 host ports.
Topology: 1:4 fanout — one Quantum-2 / SN5600 OSFP port serves four NDR200 hosts. The port must be configured in 4× NDR200 fanout mode in UFM, NVOS, or Cumulus Linux.
Reach: 3m. Intra-rack runs and immediately-adjacent rack within the same AI-cluster row. Not for inter-row, EoR / MoR aggregation, or DCI.
Firmware / EEPROM: Lenovo-branded vendor data. On non-Lenovo hosts, validate acceptance under the platform's cable-vendor enforcement policy before scale deployment.


Frequently Asked Questions (FAQ)
Q. What is the LENOVO Mellanox 03GX912?
The 03GX912 is a Lenovo-branded NVIDIA Mellanox LinkX passive copper splitter cable. It breaks one 800G OSFP switch port into four 200G QSFP112 NDR200 host links in a 3-metre passive copper assembly. It is the Lenovo OEM equivalent of NVIDIA Mellanox P/N MCP7Y40-N003.
Q. Is the 03GX912 a single-connector OSFP cable or a hybrid splitter?
It is a hybrid 1:4 splitter, switch end OSFP, adapter ends QSFP112. The switch side is one OSFP plug at 800G; the adapter side is four independent QSFP112 plugs at 200G NDR200 each. It is not a 1-to-1 OSFP-to-OSFP cable, and it is not an all-QSFP112 cable.
Q. Which switches and adapters does the 03GX912 connect?
Switch side: NVIDIA Quantum-2 (QM9700 / QM9790) InfiniBand or NVIDIA Spectrum-4 SN5600 Ethernet, each providing 800G OSFP cages in 4x NDR200 fanout mode. Adapter side: NVIDIA ConnectX-7 NDR200 single-port and dual-port adapters or NVIDIA BlueField-3 NDR200 DPUs with QSFP112 host ports.
Q. Is this cable for AI training or for general-purpose enterprise networking?
NDR200 at 200G per host is in the AI training, GPU-interconnect, and large-HPC workload class. The 1:4 fanout topology is specifically optimised for high-density NDR200 GPU-node clusters where a single 800G switch port serves four NDR200 servers - typical AI-cluster east-west fabric. It is not intended for 10 / 25 / 40 GbE enterprise data ports.
Q. Why is the cable labelled LENOVO rather than NVIDIA?
03GX912 is the Lenovo OEM SKU for the NVIDIA Mellanox MCP7Y40-N003. The cable and silicon are NVIDIA Mellanox; the EEPROM is coded for Lenovo ThinkSystem servers and Lenovo-branded switches. Functionally identical on the wire; firmware-vendor enforcement on the host determines whether non-Lenovo platforms accept the EEPROM without warning.
Q. Can the 03GX912 be deployed between racks, or only inside one rack?
At 3 metres this passive copper DAC is intended for intra-rack deployment or runs to an immediately-adjacent rack within the same AI-cluster row. It is not designed for inter-row, EoR / MoR aggregation, or DCI - those distances require ACC or AOC cables.
Q. What condition is supplied by T.E.S IT-SOLUTIONS?
New unit. Identified by MPN before despatch - matched against NVIDIA P/N MCP7Y40-N003 reference, length, and connector configuration - and shipped from EU stock in anti-static packaging.

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 teams since 2007. Every unit — NVIDIA-branded or OEM rebrand such as this Lenovo 03GX912 — is identified by MPN, equivalent vendor P/N, length, and connector configuration before despatch, with free pre-sale compatibility advice for switch, adapter, and fanout-mode pairing. EU stock, global B2B shipping.