NVIDIA Mellanox MSB7890-ES2R Switch-IB 2 EDR 100Gb/s 36-Port QSFP28 InfiniBand 1U Switch: This is an externally managed 1U InfiniBand switch built on the Switch-IB 2 ASIC with 36 non-blocking QSFP28 ports operating at 100Gb/s EDR per port. The unit ships with reverse airflow (power-to-connector) for hot-aisle/cold-aisle layouts where the switch faces away from the cold aisle. This is an unmanaged-control-plane platform: subnet management must be provided by another Mellanox managed switch (MSB7800) or by host-based OpenSM. It is not a standalone managed fabric controller. This is a refurbished unit.
Engineering Context
The MSB7890-ES2R provides aggregate bidirectional throughput of 7.2 Tb/s across 36 EDR ports. Each QSFP28 port runs at 4 lanes of 25Gb/s NRZ for 100Gb/s line rate. Adaptive Routing and SHARP (Scalable Hierarchical Aggregation and Reduction Protocol) acceleration are supported in hardware via the Switch-IB 2 silicon. Cut-through latency is sub-90ns port-to-port. The switch uses 1+1 redundant hot-swap PSUs and N+1 redundant hot-swap fans. Power consumption is rated at approximately 136W typical. Reverse airflow direction is fixed in this SKU and cannot be reversed in field.
Deployment & Use Cases
HPC compute clusters running MPI workloads such as LAMMPS, GROMACS, OpenFOAM, and WRF. GPU-Direct RDMA fabrics for NVIDIA HGX/DGX systems where leaf switches need EDR connectivity to ConnectX-4/5 adapters. Storage backend networks for Lustre, GPFS, and BeeGFS over InfiniBand. Spine layer in two-tier fat-tree topologies where another switch provides subnet management.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MSB7890-ES2R
ASIC: Switch-IB 2
Ports: 36 x QSFP28
Port Speed: 100Gb/s EDR InfiniBand
Aggregate Throughput: 7.2 Tb/s
Latency: Sub-90ns port-to-port (cut-through)
Management: Externally managed (no onboard subnet manager)
Airflow: Reverse (P2C, power-to-connector)
Form Factor: 1U Rackmount
Power: 1+1 Redundant Hot-Swap PSU, ~136W typical
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Compatible with NVIDIA Mellanox ConnectX-4, ConnectX-5, and ConnectX-6 EDR/HDR100 adapters. Operates with passive copper QSFP28 cables (MCP1600 series) up to 3m, active optical cables (MFA1A00 series) up to 100m, and EDR transceivers. Not compatible with FDR-only HCAs at full speed; FDR adapters will negotiate down. Requires an external subnet manager — either a managed switch (e.g., MSB7800) or host-based OpenSM. Reverse airflow only; do not deploy in cabinets requiring port-to-power airflow. Not a Spectrum Ethernet switch — this unit is InfiniBand-only and does not support standard Ethernet protocols.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS load-tests every InfiniBand switch for port integrity, PSU redundancy, fan health, and firmware boot before shipment. We provide expert consultation on EDR fabric design, global shipping with 1-3 day handling, and warranty backed by stocked spares. Visit tes-itsolutions.com for fabric architecture support.