NVIDIA Mellanox MCX354A-FCBT ConnectX-3 VPI Dual-Port QSFP FDR InfiniBand 56Gb/s and 40/56GbE, PCIe 3.0 x8: This is a dual-port Virtual Protocol Interconnect (VPI) adapter card built on the Mellanox ConnectX-3 ASIC. Each QSFP port can independently run InfiniBand FDR (56Gb/s) or Ethernet (40GbE / 56GbE Mellanox mode). The card connects to the host over a PCIe 3.0 x8 slot. This is a server adapter card, not a switch and not a transceiver. Tall (full-height) PCIe bracket. This is a brand-new factory-sealed unit.
Engineering Context
The MCX354A-FCBT belongs to the ConnectX-3 VPI family, where each port can be configured independently as InfiniBand (up to FDR 56Gb/s, 4x14Gb/s) or Ethernet (40GbE IEEE 802.3ba, or 56GbE Mellanox proprietary). The PCIe 3.0 x8 host interface (8 GT/s, ~63 Gb/s usable) is the bandwidth ceiling — running both ports at 56Gb/s simultaneously will be host-PCIe-limited, not link-limited. The ASIC supports RoCE v1, RDMA over IB, hardware-based congestion control, and SR-IOV for virtualization.
Deployment & Use Cases
HPC compute nodes connecting to FDR InfiniBand fabrics with SwitchX-2 (SX6036, SX6018) or earlier. Storage targets that present both IB (Lustre, GPFS over RDMA) and Ethernet (NFS) on the same card. Legacy data center upgrades from QDR to FDR. OpenStack control planes where dual-port redundancy is required at modest cost. Bridging clusters where one port is IB and the other Ethernet.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number (MPN): MCX354A-FCBT
Controller / ASIC: ConnectX-3 VPI
Ports: 2 x QSFP (each independently configurable IB or Ethernet)
InfiniBand Rates: SDR / DDR / QDR / FDR10 / FDR (up to 56Gb/s per port)
Ethernet Rates: 10 / 40 / 56GbE per port (56GbE is Mellanox proprietary)
Host Interface: PCI Express 3.0 x8 (8 GT/s)
Bracket: Tall (full-height)
RDMA: Native RDMA over IB; RoCE v1 over Ethernet
SR-IOV: Supported
Form Factor: Standard PCIe card with tall bracket installed
Condition: New — Factory-sealed
Compatibility & Hard Constraints
FDR InfiniBand requires a Mellanox SwitchX-2 or newer IB switch (SX6018, SX6036, SB7700, etc.). 56GbE Ethernet operation is Mellanox proprietary and requires a Mellanox SX1036/SX1024/SN2700 (in 56G mode) on the other end. Standard 40GbE is IEEE 802.3ba compliant and works with any vendor's QSFP+ switch. PCIe 3.0 x8 host bandwidth is the bottleneck for sustained dual-port 56Gb/s. RoCE v2 is not supported on ConnectX-3 (RoCE v1 only). Driver support: MLNX_OFED on Linux, WinOF on Windows, ESXi 6.0+. ConnectX-3 is end-of-life from NVIDIA — no new firmware features.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS supplies factory-new ConnectX-3 VPI cards in original packaging, and provides expert consultation on legacy InfiniBand and 40/56GbE fabrics, global shipping, and a 1–3 day handling time. Visit tes-itsolutions.com for the full catalog.