NVIDIA Mellanox MCX455A-FCAT ConnectX-4 VPI Single-Port QSFP28 Adapter, FDR 56Gb/s InfiniBand and 40/56GbE, PCIe 3.0 x16: This is a ConnectX-4 Virtual Protocol Interconnect (VPI) network adapter that supports both InfiniBand FDR and Ethernet on a single QSFP28 port. The card is a PCIe 3.0 x16 host interface adapter for rack-mount servers. It is NOT an EDR/100G card — the FCAT SKU is rated for FDR 56Gb/s InfiniBand and up to 56GbE Ethernet, even though the QSFP28 cage is shared with higher-speed ConnectX-4 SKUs. This is a refurbished unit.
Engineering Context
The ConnectX-4 VPI silicon allows the port to be configured at boot time as either InfiniBand or Ethernet through firmware (mlxconfig LINK_TYPE_P1). Maximum InfiniBand rate is FDR (56Gb/s, 4x14Gb/s NRZ), and maximum Ethernet rate is 56GbE (or 40GbE for standards-only links). The PCIe 3.0 x16 slot provides 128Gb/s of host bandwidth, sufficient to saturate a single 56Gb/s port with headroom for control traffic. The card supports RDMA over both InfiniBand (native) and Ethernet (RoCEv1/v2), plus hardware offloads for SR-IOV, GPUDirect, and overlay networks (VXLAN/NVGRE/Geneve).
Deployment & Use Cases
HPC clusters running MPI workloads over InfiniBand FDR. Storage fabrics serving NVMe-oF over RoCEv2 at 40/56GbE. Mixed-protocol clusters where the same hardware is repurposed between InfiniBand and Ethernet workloads. GPU-attached compute nodes using GPUDirect RDMA for low-latency tensor exchange. Dense virtualization hosts requiring SR-IOV with up to 127 virtual functions per port.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MCX455A-FCAT
Controller: ConnectX-4 VPI
Ports: Single QSFP28
InfiniBand: FDR 56Gb/s, FDR10, QDR, DDR, SDR
Ethernet: 56GbE, 40GbE, 25GbE, 10GbE, 1GbE
Host Interface: PCIe 3.0 x16 (8GT/s/lane)
Form Factor: Standard PCIe full-height/half-length
RDMA: InfiniBand verbs, RoCEv1/v2
Virtualization: SR-IOV up to 127 VFs/port
RoHS: R6 compliant
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Constraints
Compatible with PCIe 3.0 x16 slots; will function in x8 slots at reduced bandwidth (downshift) and in x16 Gen2 slots at half PCIe rate. Host driver supported on Linux (MLNX_OFED, inbox kernel ≥3.10), Windows Server 2012 R2/2016/2019, VMware ESXi 6.x/7.x, and FreeBSD. Not an EDR (100Gb/s) card — do NOT specify for fabrics requiring EDR or HDR. For 100GbE Ethernet, MCX455A-ECAT or higher is required. QSFP28 cage accepts FDR-rated AOC, DAC, and optical transceivers; using EDR transceivers will negotiate down to FDR. Single-port only — no port-level redundancy on a single card.
Why TES
T.E.S IT-SOLUTIONS bench-tests every ConnectX-4 adapter for link establishment on both InfiniBand and Ethernet modes, firmware health, and PCIe link width before shipment. Visit tes-itsolutions.com for fabric design assistance and bulk pricing. Handling time 1–3 business days with international shipping.