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.
Frequently Asked Questions
What host bus does the MCB191A-FCAT have?
The MCB191A-FCAT host bus is PCIe 3.0 x8 (8 GT/s), as listed in the specifications for MCB191A-FCAT.
What is the MCB191A-FCAT NOT compatible with?
This is an HCA for InfiniBand fabrics, not an Ethernet NIC and not a VPI card. Confirm fitment against your platform before ordering MCB191A-FCAT.
What condition is the MCB191A-FCAT supplied in, and who sells it?
The MCB191A-FCAT is supplied in Refurbished condition by T.E.S IT-SOLUTIONS from EU stock, with 1-3 business day handling and worldwide B2B shipping. See https://www.tes-itsolutions.com/product-page/mellanox-mcb191a-fcat-connect-ib-host-channel-adapter-single-port-qsfp-fdr-56gb.