NVIDIA Mellanox MCX631102AC-ADAT ConnectX-6 Lx EN, Dual-Port 25GbE SFP28, PCIe 4.0 x8, Crypto + Secure Boot: This is a dual-port 25 Gigabit Ethernet network adapter card based on the ConnectX-6 Lx ASIC (Lightweight, cost-optimized variant of the ConnectX-6 family), with both Secure Boot and inline cryptographic offload enabled (suffix -AC). This is a host-side NIC for installation in a server PCIe slot. This is NOT a switch, transceiver, or InfiniBand adapter, and does NOT support 100GbE. This is a refurbished unit, fully tested by T.E.S IT-SOLUTIONS.
Engineering Context
The MCX631102AC-ADAT carries OEM part number 900-9X662-0083-ST0. Each SFP28 port supports 1/10/25 Gigabit Ethernet, with auto-negotiation between rates. The PCIe 4.0 x8 host interface delivers approximately 15.75GB/s of usable bandwidth, sufficient for line-rate dual-25GbE traffic with overhead for offloads. The -AC variant adds inline IPsec/TLS cryptographic offload and Secure Boot to the ConnectX-6 Lx baseline. ConnectX-6 Lx is positioned as a 25/50GbE-class adapter; this -ADAT SKU is the dual-port 25GbE variant.
Deployment & Use Cases
Mainstream cloud and enterprise data center 25GbE NIC for server uplinks. Multi-tenant cloud requiring inline IPsec for tenant isolation at the NIC. Hypervisor host networking for VMware ESXi, KVM, and Hyper-V using SR-IOV. NVMe-oF over RoCEv2 storage initiators on 25GbE fabrics. Edge compute and telco environments needing hardware-accelerated TLS offload. ToR-attached compute nodes on 25GbE leaf switches.
Technical Specifications
OEM: NVIDIA Mellanox
Part Number: MCX631102AC-ADAT (900-9X662-0083-ST0)
Controller: ConnectX-6 Lx
Ports: 2x SFP28
Supported Speeds per Port: 1/10/25GbE
Aggregate Line Rate: 50Gb/s (2x25GbE)
Host Interface: PCIe 4.0 x8 (backward compatible to 3.0)
Form Factor: HHHL (with bracket as supplied)
Security: Secure Boot + inline IPsec/TLS crypto offload
Offloads: RoCEv2, NVMe-oF, SR-IOV, ASAP² (firmware-dependent)
Protocol: Ethernet (EN) only
Condition: Refurbished — tested by T.E.S IT-SOLUTIONS
Compatibility & Constraints
Compatible with NVIDIA Spectrum and any standards-compliant 25GbE SFP28 leaf switch. Use NVIDIA-approved 25GbE SFP28 transceivers, DAC, or AOC cables; some third-party optics may require coding-check overrides. Not compatible with InfiniBand fabrics. Maximum per-port speed is 25GbE — does NOT support 50GbE or 100GbE on this dual-port SKU. PCIe 4.0 x8 slot recommended for full bandwidth; will operate at PCIe 3.0 speeds with reduced throughput. Crypto-enabled (-AC) units may be subject to import/export controls in some jurisdictions; verify regulatory requirements. The -AS variant of this same card omits crypto.
Why TES
T.E.S IT-SOLUTIONS tests every ConnectX-6 Lx adapter end-to-end: link bring-up on both SFP28 ports, PCIe link-width validation, Secure Boot verification, and firmware integrity check. Visit tes-itsolutions.com for compatibility consultation. Handling time: 1-3 business days.