How is the port mode (InfiniBand vs Ethernet) selected on the MCX555A-ECAT?

VPI port mode is set via the mlxconfig utility (LINK_TYPE_P1=1 for IB, LINK_TYPE_P1=2 for Ethernet) followed by a host reboot. The setting is stored in the card's NVRAM and persists across power cycles. PCIe Gen3 x16 (~128 Gb/s usable) provides headroom above the 100 Gb/s line rate.

Is the MCX555A-ECAT a dual-port or Socket Direct card?

No. The MCX555A-ECAT is a single-port single-PCIe-slot adapter. For dual-port use the MCX556A-ECAT, and for Socket Direct (dual-PCIe to two CPU sockets) use the MCX556M-ECAT-S35A. The MCX555A-ECAT is also not designed for HDR (200Gb/s) — that requires ConnectX-6.

Is the refurbished MCX555A-ECAT tested?

Yes. T.E.S IT-SOLUTIONS power-tests every ConnectX-5 VPI adapter, validates 100Gb/s link training, and verifies firmware rev. The full Mellanox VPI catalog is at https://www.tes-itsolutions.com/.

NVIDIA Mellanox MCX555A-ECAT ConnectX-5 VPI Single-Port 100Gb/s EDR/100GbE Adapter: This is a ConnectX-5 VPI host adapter with a single QSFP28 port that operates either as 100Gb/s EDR InfiniBand or as 100GbE Ethernet, selectable per-deployment. The card uses a single PCIe Gen3 x16 host interface and ships with a tall (full-height) bracket. NVIDIA P/N: 900-9X5AD-0016-ST0. This is a single-port adapter — not dual-port, and not Socket Direct. This is a refurbished unit.

Engineering Context

VPI (Virtual Protocol Interconnect) means the same QSFP28 cage runs InfiniBand or Ethernet under driver control — the protocol is selected at the OS level via mlxconfig or PORT_TYPE settings, not at manufacture time. PCIe Gen3 x16 yields ~128 Gb/s of usable host bandwidth, more than enough headroom for a single 100Gb/s port. ConnectX-5 silicon supports RoCEv2, NVMe-oF target/initiator, T10-DIF data integrity, hardware-accelerated erasure coding, and stateless TCP/UDP/IP offloads. SR-IOV is supported with up to 1K virtual functions per host.

Deployment & Use Cases

Single-port HPC compute nodes attached to EDR InfiniBand fabrics running MPI workloads. AI/ML training nodes where one 100Gb/s port suffices per server. NVMe-oF initiators or storage-side targets. Lustre and GPFS (Spectrum Scale) client nodes. Hybrid environments where the same hardware is repurposed between IB and Ethernet via firmware reconfiguration.

Technical Specifications

OEM: NVIDIA Mellanox
Part Number: MCX555A-ECAT (NVIDIA P/N 900-9X5AD-0016-ST0)
Family: ConnectX-5 VPI
Ports: Single QSFP28
Data Rate: 100Gb/s EDR InfiniBand or 100GbE Ethernet (VPI)
Host Interface: PCIe Gen3 x16
Bracket: Tall (Full-Height)
RDMA: RoCEv2 (Ethernet) and native InfiniBand verbs
Offloads: NVMe-oF, T10-DIF, erasure coding, stateless TCP/UDP/IP
Virtualization: SR-IOV (up to 1K VFs)
Driver: MLNX_OFED / WinOF-2 / inbox kernel drivers
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS

Compatibility & Constraints

Requires one PCIe x16 slot (Gen3 electrical or better). Compatible with NVIDIA Quantum / Switch-IB EDR InfiniBand switches and Spectrum/Spectrum-2/Spectrum-3 100GbE switches. Port mode (IB vs Ethernet) is set with mlxconfig (LINK_TYPE_P1) and requires a host reboot. Not designed for HDR (200Gb/s) or NDR — those need ConnectX-6 or ConnectX-7. Not compatible with SFP28 cages (form factor mismatch). Single-port card — for redundancy or socket-bound dual rails, use MCX556A-ECAT (dual-port) or MCX556M-ECAT-S35A (Socket Direct).

Why Choose T.E.S IT-SOLUTIONS

T.E.S IT-SOLUTIONS power-tests every ConnectX-5 VPI adapter, validates 100Gb/s link training in both IB and Ethernet port modes where applicable, and verifies firmware rev. Visit https://www.tes-itsolutions.com/ for our full Mellanox VPI catalog. Handling time: 1–3 business days.

NVIDIA Mellanox® MCX555A-ECAT ConnectX-5 VPI 100GbE/EDR Single-Port QSFP28

Name: NVIDIA Mellanox® MCX555A-ECAT ConnectX-5 VPI 100GbE/EDR Single-Port QSFP28
SKU: MCX555A-ECAT_Refurbished

SKU: MCX555A-ECAT_Refurbished

€400.00

Quantity