NVIDIA Mellanox MCX654106A-HCAT ConnectX-6 VPI 200Gb/s Dual QSFP56 Socket Direct Adapter: This is a ConnectX-6 VPI network adapter card with two QSFP56 ports, each capable of 200Gb/s HDR InfiniBand or 200GbE Ethernet. The card uses Socket Direct architecture, presenting two PCIe Gen3/Gen4 x16 host interfaces (a primary card plus an auxiliary card connected via harness) so each port can map directly to a separate CPU socket. NVIDIA P/N: 900-9X6B4-0058-DT0. This is a tall-bracket FHFL adapter, not a low-profile card and not a single-slot card. This is a new, factory-sealed unit.
Engineering Context
VPI (Virtual Protocol Interconnect) lets each port operate independently as InfiniBand HDR (200Gb/s) or Ethernet (200GbE / 100GbE / 50GbE / 25GbE / 10GbE), selectable in software. Socket Direct splits the PCIe lanes across two physical x16 slots so dual-socket servers avoid traversing the QPI/UPI inter-socket link for I/O — reducing NUMA latency for dual-CPU AI and HPC nodes. The ConnectX-6 ASIC supports RDMA over Converged Ethernet (RoCE), GPUDirect RDMA, GPUDirect Storage, hardware-offloaded MPI tag matching, and PCIe Gen4 host signaling.
Deployment & Use Cases
Dual-socket AI training servers (DGX-class equivalents) where both CPUs need direct fabric access. HDR 200Gb/s InfiniBand storage backends with RDMA and GPUDirect Storage. 200GbE leaf-spine fabric uplinks in hyperscale data centers. NVMe-oF target/initiator nodes requiring deterministic latency. Mixed IB/Ethernet labs where the same card must service both fabric types per port.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number (MPN): MCX654106A-HCAT
NVIDIA P/N: 900-9X6B4-0058-DT0
ASIC: ConnectX-6 VPI
Ports: 2 × QSFP56
Data Rate per Port: 200Gb/s HDR InfiniBand or 200GbE Ethernet (down-shift to 100/50/25/10G)
Host Interface: Socket Direct — 2 × PCIe Gen3/Gen4 x16
Bracket: Tall (Full-height)
Form Factor: FHFL (dual-slot, primary + auxiliary card with harness)
Protocol Support: InfiniBand HDR/HDR100/EDR/FDR, Ethernet 200/100/50/25/10G
RDMA Features: RoCE v1/v2, GPUDirect RDMA, GPUDirect Storage
Condition: New — Factory-sealed
Compatibility & Hard Constraints
Requires two adjacent (or harness-routable) PCIe x16 slots on the host — not usable in single-slot servers. Best performance on PCIe Gen4 hosts; will function at Gen3 speeds on Gen3 platforms. Compatible with NVIDIA Quantum HDR switches (QM87xx) and Spectrum-2/Spectrum-3 Ethernet switches (SN3000/SN4000) using QSFP56 cables/AOCs. Not compatible with QSFP-DD or OSFP ports without a media converter. Not compatible with NDR (400Gb/s) fabrics — use ConnectX-7 OSFP cards for NDR. The Socket Direct harness is required — verify the harness is included before deployment.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS verifies port link, PCIe lane training on both x16 interfaces, and Socket Direct harness continuity on every adapter before shipment. We provide compatibility consultation for HDR fabric and dual-socket Socket Direct deployments, global shipping with handling time of 1–3 business days, and direct technical support. Visit www.tes-itsolutions.com for the full inventory.