NVIDIA Mellanox MCX623435AC-VDAB ConnectX-6 Dx EN OCP 3.0 Adapter, 200GbE, Single-Port QSFP56, Crypto + Secure Boot, PCIe Gen4 x16: The MCX623435AC-VDAB is a single-port ConnectX-6 Dx EN (Ethernet-only) network adapter in the OCP 3.0 SFF (Small Form Factor) mezzanine form factor, operating at up to 200GbE on one QSFP56 cage. This is an OCP 3.0 mezzanine card — it is not a standard PCIe add-in card and will not fit a standard PCIe slot. The -AC-VDAB suffix indicates the crypto + Secure Boot variant. This is a refurbished unit, tested by T.E.S IT-SOLUTIONS.
Engineering Context
The card connects through the OCP 3.0 SFF edge connector, electrically equivalent to PCIe 4.0 x16 (≈31.5 GB/s usable host bandwidth). ConnectX-6 Dx silicon implements RDMA over Converged Ethernet v2 (RoCE v2), NVMe-oF target/initiator, GPUDirect RDMA, hardware-accelerated VXLAN/GENEVE/NVGRE encapsulation, OVS offload via ASAP² Direct, and Connection Tracking offload. The crypto engine performs inline IPsec ESP and TLS 1.2/1.3 record encryption/decryption at line rate. Secure Boot enforces signed-firmware verification at adapter power-on, anchoring the platform root of trust. Host Management is supported, allowing BMC sideband access via NC-SI.
Deployment & Use Cases
OCP 3.0 hyperscale cloud servers (HPE ProLiant Gen10 Plus / Gen11 OCP slots, Dell PowerEdge R7525/R7625 OCP, Supermicro Big Twin OCP, Lenovo ThinkSystem OCP); secure multi-tenant cloud platforms requiring inline IPsec; financial and government data centers with FIPS firmware-signing requirements; AI/ML training nodes on Spectrum Ethernet; NVMe-oF storage initiators in modular cloud chassis; and bare-metal cloud nodes needing line-rate TLS termination with Secure Boot enforcement.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MCX623435AC-VDAB
Product Family: ConnectX-6 Dx EN
Form Factor: OCP 3.0 SFF (Small Form Factor)
Ports: 1 × QSFP56
Ethernet Speeds: 200GbE, 100GbE, 50GbE, 40GbE, 25GbE, 10GbE, 1GbE
Maximum Per-Port Rate: 200Gb/s
Host Interface: PCIe 4.0 x16 over OCP edge
Crypto: Enabled (inline IPsec + TLS 1.2/1.3)
Secure Boot: Enabled
Host Management: NC-SI sideband supported
Bracket: OCP 3.0 thumbscrew + pull-tab
Condition: Refurbished — Tested by T.E.S IT-SOLUTIONS
Compatibility & Constraints
Compatible with NVIDIA Spectrum-2 (SN3000) and Spectrum-3 (SN4000) Ethernet switches at 200GbE. Supports QSFP56 PAM4 DACs, AOCs, and transceivers; mechanically backward compatible with QSFP28 100GbE optics. Not compatible with OSFP or QSFP-DD cages. Requires an OCP 3.0 SFF host slot — does NOT fit standard PCIe add-in slots; confirm server has an OCP 3.0 NIC bay before purchase. This is an Ethernet-only NIC; does NOT run InfiniBand. Driver support requires MLNX_OFED or in-tree mlx5 driver; supported on Linux, Windows Server, and VMware ESXi.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS bench-tests every MCX623435AC-VDAB for 200GbE link training on the QSFP56 port, OCP edge connector continuity, PCIe x16 negotiation, crypto/Secure Boot functionality, firmware integrity, and thermal sensor health before shipment. Handling time is 1–3 business days. Visit our product page or tes-itsolutions.com for our full ConnectX-6 Dx OCP 3.0 inventory and integration consulting.