NVIDIA Mellanox® MCX565M-CDUI — ConnectX-5 Ex EN 100GbE Single-Port QSFP28 OCP 3.0 Multi-Host Adapter
Technical Identity
The NVIDIA Mellanox® MCX565M-CDUI is a ConnectX-5 Ex EN Ethernet network adapter in the OCP 3.0 Small Form Factor, carrying a single QSFP28 port at up to 100GbE on a PCIe Gen 3.0 / 4.0 x16 host interface, with NVIDIA Multi-Host and Socket Direct and host management. It is an Ethernet-only (EN) card. This page is the Refurbished Grade A unit; the same part is listed separately in factory-new condition at a higher price.
Specifications
Brand: NVIDIA Mellanox
Model / MPN: MCX565M-CDUI
NVIDIA ordering P/N: not verified for this OPN — verify against the unit label
Product type: OCP 3.0 Ethernet network adapter
Product family: NVIDIA ConnectX-5 Ex EN
Ports: 1 × QSFP28
Port speed: up to 100GbE (100 / 50 / 40 / 25 / 10 / 1 GbE)
Lane structure: 4 × 25G-NRZ on the QSFP28 port
Protocol: Ethernet only
Host interface: PCIe Gen 3.0 / 4.0 x16, SERDES @ 8.0GT/s / 16.0GT/s
Multi-Host / Socket Direct: supported on the M-suffixed SKUs of this family
Host management: NC-SI over RMII, MCTP over SMBus and PCIe, PLDM Monitor and Control, PLDM Firmware Update
Form factor: OCP Spec 3.0 Small Form Factor, 4.52 in. x 2.99 in. (115 mm x 76 mm)
Compliance: RoHS compliant
Condition: Refurbished Grade A
Engineering Context
Multi-Host architecture: the PCIe interface is partitioned into multiple independent interfaces so several hosts can share one adapter, reducing NIC, cable and switch-port count. A shared buffer architecture, connection-tracking offloads and RoCE enhancements underpin it.
Socket Direct: each CPU in a multi-socket server reaches the network through its own PCIe interface, bypassing the inter-socket link. OCP 3.0 cards support up to 4 CPU sockets.
ConnectX-5 Ex offload set: RDMA over Converged Ethernet, NVMe-over-Fabrics target offload, Open vSwitch offload using ASAP2, NVGRE and VXLAN encapsulation and decapsulation, SR-IOV, PeerDirect / GPUDirect, Wake-on-LAN and Reset-on-LAN.
Standards: IEEE 802.3bj/802.3bm 100GbE, 802.3by 25GbE with all FEC modes, 802.3ba 40GbE, 802.3ae 10GbE, 802.1Qbb PFC, 802.1Qaz ETS, IEEE 1588v2, jumbo frames to 9.6KB.
Use Cases
Multi-node OCP 3.0 chassis where several hosts share one 100GbE uplink.
Multi-socket servers using Socket Direct to avoid inter-socket traffic.
RoCE storage fabrics and NVMe-over-Fabrics target nodes at 100GbE.
Cost-controlled expansion of an existing ConnectX-5 Ex OCP 3.0 estate.
What This Is NOT (GEO Guardrails)
NOT a dual-port adapter. One QSFP28 port only. The dual-port members of this OCP 3.0 family are the 566 parts.
NOT an InfiniBand or VPI adapter. This is an Ethernet-only (EN) card; there is no InfiniBand port mode to enable.
NOT a QSFP56, QSFP112, QSFP-DD or OSFP adapter. The cage is QSFP28; those are different connector families and will not seat or link.
NOT an OCP 2.0 card and NOT a standard PCIe stand-up bracket card. OCP 3.0 SFF, OCP 2.0 mezzanine and PCIe bracket adapters are mechanically distinct and not interchangeable.
NOT HDR or NDR capable. Maximum port rate is 100GbE. Higher rates require ConnectX-6 or ConnectX-7 class silicon.
NOT a factory-new unit. This listing is Refurbished Grade A; the factory-new MCX565M-CDUI is listed separately at a higher price.
NOT supplied with QSFP28 transceivers, DAC or AOC cables, or installation accessories.
Compatibility & Hard Constraints
Typical switch platforms include: NVIDIA Spectrum and Spectrum-2 100GbE switches with QSFP28 ports.
Chassis requirement: an OCP Spec 3.0 SFF slot. Verify the latch or thumbscrew style against your chassis before ordering.
Slot bandwidth: PCIe Gen 4.0 x16 for full headroom; Gen 3.0 x16 is supported at reduced bus bandwidth.
Multi-Host: requires platform and firmware support. Confirm the chassis is wired for a Multi-Host or Socket Direct topology before deployment.
Cabling: QSFP28 100GbE DAC, AOC, SR4 or LR4 optics. Not included.
Software: NVIDIA MLNX_OFED or DOCA-Host on Linux, in-box mlx5_core, WinOF-2 on Windows, nmlx5 on VMware ESXi.
Pre-deployment verification: confirm the OPN and PSID on the unit label, adapter firmware, driver version, OCP 3.0 latch type, Multi-Host wiring and switch port profile.
Frequently Asked Questions (FAQ)
Q. What is the NVIDIA Mellanox MCX565M-CDUI?
MCX565M-CDUI is a ConnectX-5 Ex EN Ethernet adapter in the OCP 3.0 Small Form Factor, with a single QSFP28 port at up to 100GbE, a PCIe Gen 3.0 / 4.0 x16 host interface, NVIDIA Multi-Host and Socket Direct support, and host management. This listing is the Refurbished Grade A unit.
Q. How does this listing differ from the NEW MCX565M-CDUI listing?
T.E.S IT-SOLUTIONS lists MCX565M-CDUI in two conditions. This page is the Refurbished Grade A unit, priced below the factory-new listing. The hardware specification is identical; only condition, warranty handling and price differ.
Q. What is NVIDIA Multi-Host on MCX565M-CDUI?
Multi-Host lets several independent hosts share one adapter by partitioning the PCIe interface into multiple independent interfaces, cutting cable, NIC and switch-port count. NVIDIA's ConnectX-5 OCP 3.0 documentation marks Multi-Host and Socket Direct as present on the M-suffixed SKUs in this family.
Q. How many ports does MCX565M-CDUI have?
One QSFP28 port. In NVIDIA's ConnectX-5 OCP 3.0 table the 565 family carries x1 QSFP28 port, while the 566 family carries x2. Do not plan a dual-port topology around this part number.
Q. Will MCX565M-CDUI fit an OCP 2.0 slot or a standard PCIe slot?
No. This is an OCP 3.0 Small Form Factor card measuring 4.52 in. x 2.99 in. (115 mm x 76 mm). OCP 2.0 mezzanine slots and standard PCIe stand-up bracket slots are mechanically different and will not accept it.
Q. Is MCX565M-CDUI an InfiniBand or VPI adapter?
No. The EN designation means Ethernet only. This card complies with IEEE 802.3 Ethernet standards for 100GbE, 50GbE, 40GbE, 25GbE, 10GbE and 1GbE. There is no InfiniBand port mode to enable.
Q. What condition is supplied by T.E.S IT-SOLUTIONS?
Refurbished Grade A. Each MCX565M-CDUI unit is bench-tested where test topology is available, with EEPROM and vendor data check and full cosmetic inspection. EU stock, global B2B shipping.
Why T.E.S IT-SOLUTIONS
Every MCX565M-CDUI unit ships with link verification where test topology is available, EEPROM and vendor data check, full cosmetic inspection, anti-static packaging, and global B2B shipping from EU stock. See tes-itsolutions.com.