NVIDIA Mellanox MCB191A-FCAT Connect-IB Host Channel Adapter, Single-Port QSFP FDR 56 Gb/s: This is a single-port InfiniBand-only Host Channel Adapter built on Mellanox Connect-IB silicon, with one QSFP cage rated to FDR (56 Gb/s) per port. This is an HCA for InfiniBand fabrics, not an Ethernet NIC and not a VPI card. This is a refurbished unit, tested in working order.
Engineering Context
The MCB191A-FCAT was Mellanox's purpose-built FDR HCA between ConnectX-3 and ConnectX-4. The ASIC supports IB Verbs RDMA, hardware Atomic operations, and Dynamically Connected Transport (DCT) for scaling MPI to large rank counts. The card uses a PCIe 3.0 x8 host interface; on a single FDR port that is sufficient for line-rate one-direction traffic with PCIe overhead consuming the remaining headroom. There is no Ethernet personality on this part — it cannot be flipped to Ethernet mode.
Deployment & Use Cases
HPC compute nodes joining FDR InfiniBand fabrics for tightly coupled MPI workloads (LAMMPS, NAMD, OpenFOAM, CP2K). Storage servers running Lustre, GPFS, or NFS-RDMA over IB. Replacement HCAs for existing FDR clusters where ConnectX-3/Connect-IB cards have failed. Cost-effective entry point for laboratory or academic clusters that already run FDR switches.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MCB191A-FCAT
ASIC: Connect-IB
Ports: 1 x QSFP
InfiniBand Speed: Up to FDR 56 Gb/s
Protocol: InfiniBand only (no Ethernet, no VPI)
Host Bus: PCIe 3.0 x8 (8 GT/s)
Form Factor: Standard PCIe add-in
RDMA Features: IB Verbs, Atomics, DCT
Compliance: RoHS R6
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Compatible with Mellanox FDR switches (SX6018, SX6025, SX6036, SX6512, SX6536) and FDR-rated QSFP DAC and AOC cables. Drivers are supported in MLNX_OFED within the Connect-IB lifecycle window — verify driver currency before use on modern kernels. This card is InfiniBand-only and will not enumerate on a pure Ethernet fabric. Maximum link rate is FDR 56 Gb/s; it cannot run EDR 100 Gb/s or HDR 200 Gb/s. PCIe 3.0 x8 host slot is required for full bandwidth.
Why Choose T.E.S IT-SOLUTIONS
Each MCB191A-FCAT is bench-tested by T.E.S IT-SOLUTIONS for QSFP link-up at FDR, PCIe link training, and RDMA function before shipment. We provide expert consultation on InfiniBand fabric upgrades, global shipping, and 1–3 day handling time.