NVIDIA Mellanox MCX456A-ECAT ConnectX-4 VPI Dual-Port QSFP28 Adapter Card, EDR InfiniBand 100Gb/s and 100GbE: This is a dual-port ConnectX-4 VPI (Virtual Protocol Interconnect) Host Channel Adapter / Network Interface Card with two QSFP28 ports, supporting either EDR InfiniBand 100Gb/s or 100GbE per port. The card is a PCIe Gen3 x16 add-in adapter for server hosts; it is NOT a switch, transceiver, or cable. Condition: New, in TES IT-SOLUTIONS stock.
Engineering Context: The ConnectX-4 VPI silicon supports VPI mode, allowing each QSFP28 port to be independently configured as InfiniBand or Ethernet. The MCX456A-ECAT delivers 100Gb/s per port over a PCIe 3.0 x16 host interface (theoretical bus bandwidth ~126 Gb/s), supports RDMA over both InfiniBand (native) and Ethernet (RoCE v1/v2), and exposes hardware offloads including stateless TCP/UDP offloads, GPUDirect RDMA, and SR-IOV for virtualization. NVIDIA P/N 900-9X4AC-0056-ST3 corresponds to this MPN.
Deployment & Use Cases: Targeted at HPC compute nodes, GPU cluster servers running CUDA-aware MPI, NVMe-oF storage initiators and targets, financial low-latency trading systems, and high-throughput database and AI/ML training nodes. Common pairings include EDR InfiniBand fabrics with NVIDIA Mellanox SB7700/SB7800/SB7890 switches, or 100GbE Spectrum-based deployments.
Technical Specifications:
- MPN: MCX456A-ECAT
- NVIDIA P/N: 900-9X4AC-0056-ST3
- Silicon: ConnectX-4 VPI
- Ports: 2× QSFP28
- Per-Port Rate: 100Gb/s
- Protocols: EDR InfiniBand 100Gb/s and 100GbE (per-port selectable)
- Host Interface: PCIe Gen3 x16
- Form Factor: Standard PCIe low-profile/full-height bracket
- RDMA: InfiniBand native, RoCE v1/v2 over Ethernet
- Offloads: Stateless TCP/UDP, SR-IOV, GPUDirect RDMA
- Encoding: NRZ (4x25.78125 Gb/s for IB EDR; 4x25.78125 Gb/s for 100GbE)
- Condition: New
Compatibility & Constraints: Requires a PCIe Gen3 x16 host slot for full bandwidth (will negotiate down on Gen2 or x8 with reduced throughput). Each QSFP28 port operates independently as IB or Ethernet but cannot operate as both simultaneously. The MCX456A-ECAT is the EDR-rated variant; it is NOT the HDR (200Gb/s) ConnectX-6 variant, and it is NOT a single-port card. QSFP28 cabling (DAC, AOC, or QSFP28 transceivers + MMF/SMF) is required and sold separately.
Why TES: T.E.S IT-SOLUTIONS ships from EU stock with 1–3 day handling. Contact our team for compatibility verification, firmware guidance, and bulk pricing on multi-card cluster builds.