NVIDIA Mellanox MCX556A-ECAT ConnectX-5 Ex VPI Dual-Port QSFP28 100Gb/s PCIe 3.0 x16 Adapter: This is a dual-port VPI (Virtual Protocol Interconnect) adapter card based on the ConnectX-5 Ex controller, with two QSFP28 cages capable of 100GbE Ethernet OR EDR InfiniBand per port, and a PCIe Gen3 x16 host interface. It is shipped with a tall (full-height) bracket. This is a VPI part — each port can be independently configured for Ethernet or InfiniBand. This is a refurbished unit, tested by T.E.S IT-SOLUTIONS.
Engineering Context
The ConnectX-5 Ex controller drives QSFP28 at 100Gb/s per port (4×25G NRZ). PCIe Gen3 x16 provides about 128 Gb/s of raw host bandwidth, which is the practical limit for sustaining one 100Gb/s port at line rate; running both ports concurrently at line rate is host-PCIe-bound on Gen3 x16. The card supports RDMA (RoCE v1/v2 in Ethernet mode, native InfiniBand verbs in IB mode), GPUDirect RDMA, NVMe-oF, T10-DIF, ASAP² Direct overlay offloads (VXLAN, NVGRE, Geneve), SR-IOV with multiple virtual functions per port, and embedded PCIe switch with NVMe Emulation.
Deployment & Use Cases
HPC clusters using EDR InfiniBand fabric for MPI workloads. AI/ML training rigs with GPUDirect RDMA between NVIDIA GPUs and the fabric. NVMe-oF over RoCE storage initiators and targets on 100GbE. Financial low-latency trading nodes. VPI-converged data centers that mix Ethernet and InfiniBand on the same hardware to simplify procurement.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MCX556A-ECAT
Controller: ConnectX-5 Ex VPI
Ports: 2 × QSFP28
Data Rate: 100GbE Ethernet OR EDR InfiniBand (100Gb/s) per port
Host Interface: PCI Express Gen 3.0 x16
Protocol: VPI (Ethernet and InfiniBand)
Bracket: Tall (Full-Height)
RDMA: RoCE v1/v2, native InfiniBand verbs
GPU Acceleration: GPUDirect RDMA
Storage Offloads: NVMe-oF, T10-DIF, NVMe Emulation
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Compatible with x86 servers (Dell PowerEdge, HPE ProLiant, Supermicro, Lenovo ThinkSystem) exposing a PCIe 3.0 x16 slot. Inbox drivers ship with current Linux kernels; OFED/MOFED is recommended for full feature exposure. Requires QSFP28 transceivers or DAC/AOC cables; speed must match the configured port mode. Does NOT support 200Gb/s HDR rates — for HDR use ConnectX-6 (MCX653 series). Sustaining both ports at 100Gb/s line rate simultaneously requires PCIe 4.0 host bandwidth, which this card does not negotiate (PCIe 3.0 only).
Why Choose T.E.S IT-SOLUTIONS
Each VPI card is bench-tested for both ports in both Ethernet and InfiniBand modes before shipment. T.E.S IT-SOLUTIONS ships globally with 1–3 business day handling and provides design support for HPC and AI fabrics.