NVIDIA Mellanox® MCX653105A-ECAT — ConnectX-6 VPI Single-Port HDR100/100GbE Adapter (QSFP56, PCIe 4.0 x16)

Technical Identity
The NVIDIA Mellanox® MCX653105A-ECAT is a single-port ConnectX-6 VPI (Virtual Protocol Interconnect) adapter. The port is software-selectable between InfiniBand HDR100 and 100 Gigabit Ethernet, terminated in a single QSFP56 cage. Host interface is PCIe 4.0 x16 (auto-negotiating to PCIe 3.0 x16). The card is half-height, half-length with a tall (full-height) bracket pre-installed (denoted by the CAT suffix). Condition: Refurbished Grade A — bench-tested at T.E.S IT-SOLUTIONS for link establishment, EEPROM/VPD integrity, and cosmetic inspection.

Specifications

Brand: NVIDIA Mellanox
Part Number (MPN): MCX653105A-ECAT
Product type: ConnectX Network Adapter (HCA / NIC)
ASIC / Family: ConnectX-6
Ports: 1× QSFP56 (single-port)
Protocol: VPI — InfiniBand (HDR100 / EDR / FDR / QDR) or Ethernet (100/50/40/25/10/1 GbE), software-selectable per port
Max line rate: 100 Gb/s per port (InfiniBand HDR100 or 100 GbE)
Host bus: PCI Express 4.0 x16 (16 GT/s), backward-compatible with PCIe 3.0 x16
Form factor: Half-height, half-length PCIe card; tall bracket pre-installed
RDMA: RoCE v1/v2 over Ethernet; native InfiniBand verbs
Hardware offloads: ASAP² OVS acceleration, SR-IOV (up to 1K VFs), VXLAN/NVGRE/Geneve/GTP encap-decap, T10-DIF, IPsec inline crypto, TLS offload, Stateless TCP (TSO/LRO/Checksum)
Adaptive Routing & SHARP: Supported as IB endpoint when paired with NVIDIA Quantum HDR switches
Drivers: NVIDIA MLNX_OFED (Linux), in-box mlx5_core, WinOF-2 (Windows Server), nmlx5 (VMware ESXi)
Power: Typical 18–22 W (active, link-dependent)
Condition: Refurbished Grade A — bench-tested by T.E.S IT-SOLUTIONS


What This Is NOT

NOT a dual-port adapter. Single-port (the "1" after "MCX653" denotes port count). For dual-port at the same speed see MCX653106A-ECAT.
NOT a 200 Gb/s HDR adapter. Max line rate is 100 Gb/s (HDR100 or 100GbE). For full HDR 200 Gb/s see MCX653105A-HDAT.
NOT a ConnectX-7. ASIC is ConnectX-6 — firmware, drivers, and tuning must match this generation.
NOT Ethernet-only and NOT InfiniBand-only. This is a VPI dual-protocol card; port mode is set via mlxconfig.
NOT a Multi-Host or Socket Direct variant. Single PCIe x16 root, single host.
NOT an OSFP / QSFP-DD card. Cage is QSFP56 only; OSFP transceivers / cables will not fit.
NOT bundled with QSFP56 transceivers, DAC/AOC cables, or short bracket — sold standalone.


Compatibility

InfiniBand switches: NVIDIA Quantum HDR (MQM8700/MQM8790 series), Switch-IB 2 EDR (SB7800/SB7890), and earlier EDR/FDR fabrics — runs at the highest common rate.
Ethernet switches: NVIDIA Spectrum / Spectrum-2 / Spectrum-3 (SN2700, SN3700, SN4000-series), or any 100GbE QSFP28/QSFP56 switch from Arista, Cisco, Juniper, Dell — auto-negotiating down to 50/40/25/10/1 GbE.
Cabling — QSFP56 native: MCP1650-V00xExx (passive DAC), MFA1A00-Hxxx (HDR AOC), MMA1T00-VS (200G optical transceiver, also operates at 100G).
Cabling — QSFP28 backward compatibility: The QSFP56 cage accepts QSFP28 modules; standard 100GbE QSFP28 DAC/AOC/SR4/LR4 transceivers link at 100GbE.
Port-mode switching: mlxconfig -d <pci-id> set LINK_TYPE_P1=<1=IB | 2=ETH | 3=AUTO>, then power-cycle the host.
Server platforms: Dell PowerEdge R-series (R740/R750/R760), HPE ProLiant DL3xx/DL5xx Gen10+/Gen11, Lenovo ThinkSystem SR-series, Supermicro X11/X12/X13 dual-socket platforms with PCIe 4.0 x16 slots.
GPU pairing: Supports NVIDIA GPUDirect RDMA with A100, H100, V100, A40 GPUs on the same NUMA root.
Firmware tooling: mlxfwmanager from MLNX_OFED / MFT; current FW family is fw-ConnectX6 22.x.


Frequently Asked Questions (FAQ)
Q. What is the NVIDIA Mellanox MCX653105A-ECAT?
The MCX653105A-ECAT is a single-port ConnectX-6 VPI adapter with a QSFP56 cage, capable of 100 Gb/s InfiniBand HDR100 or 100 Gigabit Ethernet (software-selectable per port). Host bus is PCIe 4.0 x16 and the card ships with a tall full-height bracket.
Q. How do I switch the MCX653105A-ECAT between Ethernet and InfiniBand?
Use mlxconfig from MLNX_OFED / MFT: mlxconfig -d <pci-id> set LINK_TYPE_P1=<1=IB | 2=ETH | 3=AUTO> and reboot the host. AUTO lets the link auto-negotiate based on the peer switch. Drivers: MLNX_OFED on Linux, WinOF-2 on Windows Server, nmlx5 on VMware ESXi.
Q. What switches and cables are compatible with the MCX653105A-ECAT?
InfiniBand: NVIDIA Quantum HDR switches (MQM8700-series) and Switch-IB 2 EDR. Ethernet: NVIDIA Spectrum SN2700/SN3700/SN4000 100GbE switches or any 100GbE QSFP28/QSFP56 switch. Cables: QSFP56 DAC (MCP1650-V0xx), QSFP56 AOC (MFA1A00-Hxxx), QSFP56 optical transceivers (MMA1T00-VS), and standard QSFP28 100GbE DAC/AOC/SR4/LR4 modules via backward compatibility.
Q. Is this a dual-port card or single-port?
Single-port. The "1" in MCX653105 indicates one port. The dual-port equivalent at the same 100 Gb/s rate is MCX653106A-ECAT.
Q. Does the MCX653105A-ECAT support PCIe 3.0 servers?
Yes. The PCIe interface auto-negotiates down to PCIe 3.0 x16. At PCIe 3.0 x16 the host bus ceiling is ~126 Gb/s — sufficient for 100 Gb/s line rate but with reduced headroom. PCIe 4.0 x16 is recommended for sustained bidirectional 100GbE / HDR100.
Q. What workloads does this adapter accelerate?
HPC clusters with MPI over RDMA, AI/ML training fabrics with GPUDirect RDMA, NVMe-oF storage (initiator or target) over RoCE v2 or InfiniBand, virtualized data centers with SR-IOV, SDN/NFV with ASAP² hardware OVS, and TLS/IPsec offloaded edge traffic.
Q. What condition is supplied by T.E.S IT-SOLUTIONS?
Refurbished Grade A. Each unit is bench-tested by T.E.S IT-SOLUTIONS: link establishment on both 100GbE and HDR100, EEPROM/VPD integrity check, firmware audit, and full cosmetic inspection. Units ship anti-static packed from EU stock with global B2B shipping options.

Why buy from T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS is a Europe-based NVIDIA Mellanox specialist serving HPC, AI, and enterprise data-center procurement teams since 2007. We focus on a single brand, so every unit is identified by MPN, NVIDIA P/N, and ASIC generation before it ships, and every customer gets free pre-sale compatibility advice for switch, adapter, and cable pairing. Multi-currency B2B invoicing, EU stock with worldwide express options, and direct technical contact with our engineering team — not a call-center.