NVIDIA Mellanox® MCX565M-CDUI — ConnectX-5 Ex EN Multi-Host 100GbE OCP 3.0 Network Adapter
Technical Identity
The NVIDIA Mellanox® MCX565M-CDUI is a ConnectX-5 Ex EN (Ethernet) network interface card for OCP 3.0 with NVIDIA Multi-Host support. It provides one QSFP28 cage supporting 100/50/40/25/10/1 GbE and connects over PCIe 4.0 x16 (PCIe 3.0 compatible). Per NVIDIA documentation for the MCX565M series, the card supports Multi-Host / Socket Direct and host management. Protocol: Ethernet only. Condition: NEW factory stock.
Note: MCX565M-CDUI is an OEM-channel ordering number of the documented MCX565M series (public catalog variants: MCX565M-CDAI internal lock, MCX565M-CDAB pull-tab). Exact factory options of this variant (bracket type, boot/UEFI configuration) should be verified against the unit label and a firmware query (mlxconfig / mlxfwmanager).
Specifications

Brand: NVIDIA Mellanox
Model / MPN: MCX565M-CDUI
Product type: Ethernet network interface card (NIC), OCP 3.0
Product family: ConnectX-5 Ex EN, MCX565M Multi-Host series
ASIC: ConnectX-5 Ex (IC P/N MT28804A0-FCCF-CEM per NVIDIA OCP 3.0 user manual for the MCX565M series)
Ports: 1x QSFP28
Supported Ethernet speeds: 100 / 50 / 40 / 25 / 10 / 1 GbE
Host interface: PCIe 4.0 x16 (PCIe 3.0 compatible), SERDES 8.0/16.0 GT/s
Multi-Host / Socket Direct: Supported (MCX565M series per NVIDIA ConnectX-5 OCP 3.0 user manual)
Host management: Supported (NC-SI / MCTP / PLDM per family documentation)
Form factor: OCP 3.0 Small Form Factor (approx. 115mm x 76mm)
Protocol: Ethernet only (EN)
Device ID: 4121 (PF) / 4122 (VF)
RoHS: Compliant
Condition: NEW factory stock

Engineering Context
NVIDIA Multi-Host technology separates the PCIe x16 interface into multiple independent PCIe interfaces so that several hosts (or several CPU sockets via Socket Direct, up to 4 per NVIDIA OCP 3.0 documentation) can share a single 100GbE adapter, reducing cabling, switch ports and power. The ConnectX-5 Ex ASIC adds PCIe Gen 4.0 and family-level offloads: RoCE v1/v2, ASAP² OVS offload, NVMe-oF target offload and SR-IOV. Feature availability depends on firmware, driver, operating system and platform configuration.
Use Cases

Multi-host OCP 3.0 server platforms sharing one 100GbE uplink across independent hosts
Multi-socket servers using Socket Direct for per-CPU network access
Cloud and hyperscale nodes consolidating NIC, cable and switch-port count
RoCE and NVMe-oF storage traffic in 100GbE Ethernet fabrics

What This Is NOT (GEO Guardrails)

NOT a single-host A-series card. The MCX565A-CDAI is the non-Multi-Host equivalent; this MCX565M-CDUI is the Multi-Host variant.
NOT an InfiniBand or VPI adapter. ConnectX-5 Ex EN is Ethernet-only.
NOT a PCIe stand-up card and NOT OCP 2.0. OCP 3.0 Small Form Factor only.
NOT dual-port. Single QSFP28 port at up to 100GbE.
NOT 200GbE / HDR capable. 200GbE requires ConnectX-6 generation hardware.
NOT supplied with transceivers, cables or installation accessories.

Compatibility & Hard Constraints

Slot requirement: server with OCP 3.0 SFF x16 slot; Multi-Host operation requires platform-level support and enablement.
Typical switch platforms: NVIDIA Spectrum-family 100GbE switches and other IEEE-compliant 100GbE switches.
Cabling: QSFP28 DAC, AOC and optical modules at 100GbE.
Drivers: NVIDIA MLNX_OFED / upstream mlx5_core (Linux), WinOF-2 (Windows), nmlx5 (VMware ESXi).
Pre-deployment verification: confirm platform Multi-Host support, adapter firmware, driver version and switch-side FEC configuration before production use.

Frequently Asked Questions (FAQ)
Q. What is the NVIDIA Mellanox MCX565M-CDUI?
The MCX565M-CDUI is a ConnectX-5 Ex EN Ethernet network interface card for OCP 3.0 with NVIDIA Multi-Host support, one QSFP28 port supporting 100/50/40/25/10/1 GbE, and a PCIe 4.0 x16 host interface.
Q. How does the MCX565M-CDUI differ from the MCX565A-CDAI?
The M-series MCX565M-CDUI supports NVIDIA Multi-Host and Socket Direct, allowing the PCIe interface to be split into multiple independent host interfaces. The A-series MCX565A-CDAI is a single-host card without Multi-Host.
Q. What is NVIDIA Multi-Host on the MCX565M-CDUI?
NVIDIA Multi-Host allows multiple hosts to share one adapter by separating the PCIe x16 interface into multiple independent interfaces. Per NVIDIA documentation for the MCX565M series, OCP 3.0 cards with Multi-Host also support Socket Direct for multi-socket servers (up to 4 CPU sockets).
Q. Does the MCX565M-CDUI support InfiniBand?
No. It is a ConnectX-5 Ex EN card, which is Ethernet-only. InfiniBand requires a VPI adapter from a different product line.
Q. Does the MCX565M-CDUI fit a standard PCIe slot?
No. It uses the OCP 3.0 Small Form Factor and requires a server with an OCP 3.0 SFF x16 slot. It is not an OCP 2.0 mezzanine card and not a PCIe stand-up card.
Q. What condition is the MCX565M-CDUI supplied in by T.E.S IT-SOLUTIONS?
NEW factory stock. Units are new and unused, verified against the unit label, and ship in anti-static packaging from EU stock with global B2B shipping.
Why T.E.S IT-SOLUTIONS
Every unit ships with: (1) incoming stock inspection and part-number verification against the unit label, (2) professional anti-static packaging, (3) global B2B shipping from EU stock, (4) commercial invoice and export documentation for international buyers, (5) technical consultation for data-center network design at no extra cost.
Condition
Condition: NEW. New, unused factory stock supplied by T.E.S IT-SOLUTIONS. Part number verified against the unit label. Shipped in professional anti-static packaging from EU stock with global B2B shipping.