NVIDIA Mellanox MCX312A-XCBT ConnectX-3 EN Dual-Port 10GbE SFP+ PCIe 3.0 x8 Adapter: This is a brand-new dual-port 10 Gigabit Ethernet (10GbE) Network Interface Card (NIC) based on the Mellanox ConnectX-3 EN ASIC. The card uses two SFP+ cages and a PCI Express 3.0 x8 host interface. This is an Ethernet-only adapter (EN suffix), not a VPI dual-protocol adapter, and it is a NIC, not a switch. This unit is brand-new and factory-sealed.
Engineering Context
The ConnectX-3 EN family was Mellanox's third-generation 10/40GbE adapter line and is widely deployed for low-latency Ethernet, RDMA over Converged Ethernet (RoCE v1), and stateless TCP offload. The MCX312A-XCBT specifically operates at up to 10GbE per port over SFP+ DAC, AOC, or fiber transceivers. PCIe 3.0 x8 supplies sufficient host bandwidth (theoretical ≈64 Gb/s payload) to saturate both 10GbE ports concurrently. The card supports SR-IOV, hardware offload of overlay networks (VXLAN/NVGRE on supported firmware), and on-chip checksum/large-send offload.
Deployment & Use Cases
10GbE server uplinks for virtualization hosts (VMware ESXi, Microsoft Hyper-V, KVM/Linux). RoCE v1 fabrics for storage protocols such as iSER, NVMe-oF (where supported), and SMB Direct. Hyper-converged storage clusters using SFP+ ToR switches. Database and analytics nodes requiring two redundant 10GbE uplinks. Lab and test infrastructure for low-latency 10GbE workloads.
Technical Specifications
- OEM: NVIDIA Mellanox
- Part Number: MCX312A-XCBT
- Family: ConnectX-3 EN
- Ports: 2 × SFP+ (Dual-Port)
- Data Rate per Port: Up to 10GbE
- Host Interface: PCI Express 3.0 x8
- Protocol: Ethernet only (EN)
- RDMA: RoCE v1 supported
- Bracket: Tall (full-height) bracket
- Compliance: RoHS R6
- Form Factor: Low-profile PCIe card with full-height bracket
- Condition: New — Factory-sealed by T.E.S IT-SOLUTIONS
Compatibility & Hard Constraints
Compatible with any standard PCIe 3.0 x8 (or wider) slot in mainstream x86 servers from Dell, HPE, Lenovo, Supermicro, and others. Drivers available for Microsoft Windows Server, RHEL/CentOS/Rocky Linux, Ubuntu LTS, SLES, VMware ESXi, and FreeBSD via the Mellanox OFED / WinOF stack. Each SFP+ cage accepts industry-standard SFP+ DAC, SFP+ AOC, or SFP+ optical transceivers; for vendor-coded host platforms (some OEM servers), use OEM-coded transceivers. Not compatible with QSFP+ optics. Not InfiniBand-capable — this is the EN (Ethernet-only) variant; for VPI dual-mode use, see the MCX354A series. Card requires PCIe 3.0 host slot for full per-port bandwidth; PCIe 2.0 x8 will limit aggregate throughput.
Why Choose T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS verifies every adapter for power-on, host detection, and link establishment before shipment. We provide expert consultation on Mellanox ConnectX deployments, driver guidance, global shipping, and a 1–3 business day handling time. Visit https://www.tes-itsolutions.com to browse our refurbished and new NVIDIA Mellanox networking inventory.