NVIDIA Mellanox ConnectX-6 Dx 100GbE OCP 3.0 Single-Port QSFP56 Multi-Host Ethernet Adapter - MCX623435MN-CDAB
This Ethernet network interface card (NIC) is the NVIDIA Mellanox MCX623435MN-CDAB, a ConnectX-6 Dx EN 100GbE adapter in OCP 3.0 small form factor with host management, Multi-Host, and Socket Direct capabilities. This is a refurbished unit, professionally tested and validated by T.E.S IT-SOLUTIONS. It does NOT include hardware Crypto or Secure Boot functionality. It is NOT a standard PCIe HHHL card.
Engineering Context
The MCX623435MN-CDAB is built on the ConnectX-6 Dx ASIC and connects via PCIe Gen 4.0 x16 (SERDES at 16.0 GT/s), delivering 100 Gb/s throughput through a single QSFP56 port using PAM4 signaling. Its Multi-Host architecture allows multiple host CPUs to share a single physical NIC, reducing hardware costs in hyperscale deployments. Socket Direct provides dedicated PCIe lanes to each CPU socket for NUMA-optimized low-latency data paths. The adapter supports RoCE v2, RDMA, SR-IOV, NVMe-oF, VXLAN/GRE/Geneve tunnel offloads, and OVS ASAP2 direct flow steering. Backward compatibility includes 50GbE (PAM4), 40GbE, 25GbE (NRZ), 10GbE, and 1GbE speeds.
Deployment and Use Cases
The MCX623435MN-CDAB is deployed in hyperscale multi-host OCP 3.0 server architectures where a single NIC must serve multiple independent host CPUs for maximum hardware density. Socket Direct eliminates cross-socket PCIe traffic, reducing latency in NUMA-sensitive workloads such as real-time analytics on Apache Kafka or low-latency trading systems. In AI and HPC clusters, it provides GPUDirect RDMA for distributed training at 100 Gb/s with optimized CPU load distribution. Cloud service providers deploy it for dense multi-tenant environments running VMware ESXi, KVM, or containerized workloads on platforms from Dell, HPE, Lenovo, and Supermicro with OCP 3.0 mezzanine slots.
Technical Specifications
Model: MCX623435MN-CDAB
OEM Part Number: 900-9X658-0016-MB0
Product Type: ConnectX-6 Dx EN Ethernet Adapter Card (NIC)
Port: 1x QSFP56
Speed: Up to 100 Gb/s (PAM4); also supports 50/40/25/10/1 GbE
PCIe Interface: Gen 4.0 x16 (SERDES at 16.0 GT/s)
Form Factor: OCP 3.0 Small Form Factor, 115.00 mm x 76.00 mm
Bracket: Thumbscrew (Pull Tab)
Host Management: Supported
Multi-Host: Supported
Socket Direct: Supported
Crypto: Not enabled (N suffix = No Crypto)
Secure Boot: Not enabled
Offloads: RoCE v2, RDMA, SR-IOV, NVMe-oF, VXLAN/GRE, OVS ASAP2
Condition: Refurbished
Compatibility and Hard Constraints
The MCX623435MN-CDAB uses a QSFP56 connector and requires QSFP56 DAC cables, QSFP56 AOC cables, or QSFP56 transceivers. It is NOT compatible with SFP28 or SFP56 cabling without a breakout adapter. This is an OCP 3.0 mezzanine card and will NOT fit standard PCIe expansion slots. The server must have an OCP 3.0 mezzanine slot and Multi-Host-capable firmware. The MCX623435AC-CDAB is the Crypto-enabled variant without Multi-Host. The MCX623435AN-VDAB is the 200GbE variant. The MCX623106AN-CDAT is the PCIe HHHL dual-port equivalent at 100GbE. This adapter is compatible with VMware ESXi, RHEL, Ubuntu, Windows Server, and bare-metal Linux. Driver support is via NVIDIA MLNX_OFED or inbox drivers.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS provides this MCX623435MN-CDAB as a professionally refurbished unit with full functional testing, including port validation, bandwidth verification, thermal checks, and Multi-Host/Socket Direct firmware confirmation. Technical consultation is available to verify OCP 3.0 slot and Multi-Host compatibility with your specific server chassis. Global shipping is available with 1-3 business day handling time.