NVIDIA Mellanox MSN2740-CB2F1 Spectrum 100GbE 32x QSFP28 Switch Onyx 1U: The NVIDIA Mellanox MSN2740-CB2F1 is a 1U short-depth Open Ethernet switch with 32 QSFP28 ports, each capable of 100GbE line rate. It is built on the original NVIDIA Spectrum ASIC and ships with Mellanox Onyx pre-installed. This is a Spectrum-1 generation switch — not Spectrum-2 (which is the SN3xxx series), and not Spectrum-3 (which is the SN4xxx series). Airflow on the -CB2F1 SKU is front-to-back (port-side intake). This is a refurbished unit.
Engineering Context
The Spectrum ASIC delivers 6.4 Tb/s switching capacity with deterministic latency and predictable buffer behaviour. All 32 QSFP28 ports support breakout into 4× 25GbE or 2× 50GbE for higher port density. Onyx provides Layer 2/3 routing, MLAG, BGP-EVPN VXLAN, sFlow, and What-Just-Happened telemetry. The short-depth 1U chassis is designed for compact racks where standard 1.5–2RU-deep switches do not fit. Power supplies are 1+1 redundant, hot-swappable AC.
Deployment & Use Cases
Top-of-Rack 100GbE deployment in compact or edge racks. Spine layer for 25/50GbE leaf fabrics using QSFP28 breakout. AI/HPC compute interconnect at 100GbE. Storage backbone for NVMe-oF arrays. Data centers migrating from 10/40GbE to 25/100GbE without changing rack depth. Open Ethernet labs that want to evaluate Onyx, Cumulus Linux, or SONiC on Spectrum hardware.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number / MPN: MSN2740-CB2F1 (PN 920-9N110-00F7-0X1)
Switch Silicon: NVIDIA Spectrum (Spectrum-1)
Ports: 32 × QSFP28 (100GbE, 4×25 / 2×50 breakout capable)
Switching Capacity: 6.4 Tb/s
Operating System: Mellanox Onyx (pre-installed)
Form Factor: 1U short-depth rackmount
Airflow: Front-to-back (port-side intake) on this SKU
Power Supplies: 2 × hot-swappable AC, 1+1 redundant
Compliance: RoHS
Rail Kit: Not included
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Constraints
Compatible with NVIDIA Mellanox QSFP28 100G DAC/AOC/transceivers and ConnectX-4/5/6 EN adapters. Onyx supports BGP, OSPF, MLAG, and VXLAN routing. Can be reflashed to Cumulus Linux or SONiC via ONIE. Not a Spectrum-2 platform — does not support 200GbE QSFP56 optics. Not the rear-to-front airflow SKU — for reverse airflow choose the -CB2R1 variant. Rail kit is not included; brackets and rails must be sourced separately.
Why TES
T.E.S IT-SOLUTIONS tests every Spectrum switch for port-by-port link training, PSU redundancy under load, fan health, and control-plane boot before shipment. Visit tes-itsolutions.com for OS reflashing, optic compatibility, and global shipping. Standard handling time is 1–3 business days.