NVIDIA Mellanox MCX623435AC-GDAE ConnectX-6 Dx EN: This is a 50GbE OCP 3.0 adapter card with a single QSFP56 port and PCIe 3.0 x16 host interface. It is a mezzanine-form-factor NIC designed for OCP-compliant server chassis, not a standard PCIe riser card. The "Dx" designation indicates hardware-accelerated cryptographic functions (IPsec/TLS) and Secure Boot, targeting secure cloud and multi-tenant data center deployments.
Engineering Context
The MCX623435AC-GDAE delivers 50Gb/s Ethernet through a single QSFP56 port over PCIe 3.0 x16. The OCP 3.0 form factor uses an ejector latch bracket and connects through the server's mezzanine slot rather than a traditional PCIe riser. This means it will not physically fit in a standard PCIe expansion slot. The card supports host management, allowing out-of-band NIC configuration via the server BMC. NVIDIA cross-references this SKU as 900-9X658-A545-SE0.
Deployment & Use Cases
OCP-Compliant Cloud Infrastructure: Designed for hyperscale and cloud servers built to Open Compute Project specifications.
Secure Multi-Tenant Environments: Hardware crypto acceleration offloads IPsec/TLS from the host CPU, enabling encryption without throughput penalty.
Virtualized Data Centers: Supports SR-IOV, RoCE v2, and NVMe-oF for efficient virtual machine networking and storage access.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MCX623435AC-GDAE
NVIDIA P/N: 900-9X658-A545-SE0
Product Family: ConnectX-6 Dx EN
Data Rate: 50GbE
Ports: Single QSFP56
Host Interface: PCIe 3.0 x16
Form Factor: OCP 3.0 (Ejector Latch Bracket)
Security: Hardware Crypto Acceleration, Secure Boot
Host Management: Supported
Condition: Refurbished — Fully Tested by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
OCP 3.0 Only: This card requires an OCP 3.0 mezzanine slot. It does not fit in standard PCIe riser slots.
Ethernet Only: Supports Ethernet protocols (including RoCE v2, RDMA, SR-IOV). Does not support native InfiniBand.
50GbE Maximum: This SKU is limited to 50GbE. For 100GbE or 200GbE, a different ConnectX-6 Dx SKU is required.
Transceiver Compatibility: Requires QSFP56 transceivers or DAC/AOC cables rated for 50GbE operation.