Does the MCX654106A-HCAT require two PCIe slots?

Yes. As a Socket Direct adapter it uses two PCIe 3.0/4.0 ×16 slots, ideally one per CPU socket. A single-slot installation will not provide the Socket Direct benefit and will under-feed both 200Gb/s ports.

Can this adapter run as Ethernet-only?

Yes. As a VPI card it can be configured per-port for InfiniBand HDR or 200GbE Ethernet. It is not InfiniBand-only and not Ethernet-only — port mode is software selectable.

What condition is this unit and who tests it?

Refurbished. T.E.S IT-SOLUTIONS validates link training, PCIe enumeration, firmware, and thermal sensors before shipment. See tes-itsolutions.com .

NVIDIA Mellanox MCX654106A-HCAT ConnectX-6 VPI 200Gb HDR Dual QSFP56 PCIe4: The NVIDIA Mellanox MCX654106A-HCAT is a ConnectX-6 VPI host channel adapter (HCA) with dual QSFP56 ports, supporting both 200Gb/s HDR InfiniBand and 200GbE Ethernet on the same card. This is a Socket Direct adapter that occupies two PCIe slots (2 × PCIe 3.0/4.0 ×16) in a full-height, full-length form factor with a tall bracket. This is not a single-slot card, and not an Ethernet-only NIC — it is a dual-protocol VPI card with Socket Direct architecture. This is a refurbished unit.

Engineering Context

Socket Direct connects the adapter to two CPU sockets simultaneously through two PCIe ×16 buses, eliminating CPU-to-CPU NUMA traversal for traffic served by the second CPU. PCIe 4.0 ×16 provides up to 256 Gb/s of usable bandwidth per slot, sufficient to feed both 200Gb/s lanes without PCIe bottlenecking. The card supports RDMA, RoCEv2, NVMe-oF, and GPUDirect for direct GPU-to-NIC DMA. The QSFP56 ports run 4× 50Gb/s PAM4 lanes per port. Hardware offloads include T10-DIF, Tunneling, and SR-IOV with up to 1K virtual functions per port.

Deployment & Use Cases

AI training fabrics in NVIDIA DGX-style clusters where each node connects to two leaf switches over HDR. HPC MPI workloads using verbs and OpenMPI over InfiniBand. NVMe-oF storage initiators and targets where GPUDirect Storage avoids CPU bounce buffers. 200GbE Ethernet leaf-to-spine uplinks in hyperscale Spectrum fabrics. Dual-CPU servers where Socket Direct removes the QPI/UPI bottleneck for the second socket.

Technical Specifications

OEM: NVIDIA Mellanox
Part Number / MPN: MCX654106A-HCAT (PN 900-9X6B4-0058-DT0)
Adapter Family: ConnectX-6 VPI
Ports: 2 × QSFP56
Data Rate: 200Gb/s HDR InfiniBand or 200GbE Ethernet (per port)
Host Interface: 2 × PCIe 3.0/4.0 ×16 (Socket Direct)
Form Factor: FHFL (Full-Height, Full-Length), dual-slot
Bracket: Tall
Offloads: RDMA, RoCEv2, NVMe-oF, GPUDirect, SR-IOV
Encoding: 4 × 50Gb/s PAM4 per QSFP56 port
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS

Compatibility & Constraints

Compatible with NVIDIA Quantum HDR InfiniBand switches (QM87xx series) and NVIDIA Spectrum 200GbE switches (SN3700/SN3800). Pairs with QSFP56 200G AOC/DAC cabling. Requires two adjacent PCIe ×16 slots and a chassis that supports Socket Direct cabling. Not compatible with single-slot servers or chassis that lack the auxiliary PCIe slot. Not a single-port card. Driver support requires MLNX_OFED or upstream Linux kernel rdma-core 28+. The card is full-height; low-profile chassis are not supported.

Why TES

T.E.S IT-SOLUTIONS tests every ConnectX-6 VPI adapter for link training on both ports, PCIe enumeration on both buses, firmware integrity, and thermal sensors before shipment. Visit tes-itsolutions.com for inventory questions, compatibility consultation, and global shipping. Standard handling time is 1–3 business days.

NVIDIA Mellanox® MCX654106A-HCAT ConnectX-6 VPI 200Gb HDR Dual QSFP56 PCIe4

Name: NVIDIA Mellanox® MCX654106A-HCAT ConnectX-6 VPI 200Gb HDR Dual QSFP56 PCIe4
SKU: MCX654106A-HCAT_Refurbished

SKU: MCX654106A-HCAT_Refurbished

€850.00

Quantity