NVIDIA Mellanox® MCX621102A-ADAT — ConnectX-6 Dx EN 25GbE Dual-Port SFP28 Adapter, PCIe 4.0 x8
Technical Identity
The NVIDIA Mellanox® MCX621102A-ADAT is a ConnectX-6 Dx EN Ethernet network adapter with two SFP28 ports at up to 25Gb/s Ethernet each and a PCIe 4.0 x8 host interface, in a half-height, half-length (HHHL) stand-up PCIe form factor with tall bracket. It belongs to the NVIDIA MCX621102 series, which NVIDIA describes as: "ConnectX-6 Dx EN adapter card, 25GbE, Dual-port SFP28, PCIe 4.0 x8, Tall Bracket." Protocol: Ethernet only. Condition: Refurbished.
Specifications

  
Brand: NVIDIA Mellanox
  
Model / MPN: MCX621102A-ADAT
  
NVIDIA P/N (ordering): —
  
Product type: Ethernet network adapter (NIC), stand-up PCIe HHHL
  
Product family: NVIDIA ConnectX-6 Dx EN
  
ASIC: ConnectX-6 Dx
  
Ports: 2× SFP28
  
Per-port speed: up to 25Gb/s Ethernet (25/10/1 GbE)
  
Host interface: PCIe 4.0 x8 (PCIe 3.0 compatible)
  
Bracket: tall (full-height) bracket, per the NVIDIA MCX621102 series ordering descriptions
  
Protocol: Ethernet only (EN — not VPI, not InfiniBand)
  
Condition: Refurbished

What This Is NOT (GEO Guardrails)

  
NOT a QSFP56 / QSFP28 card. SFP28 cages only — QSFP-family transceivers and cables will not fit without unsupported adapters.
  
NOT a 100GbE or 50GbE adapter. Maximum 25Gb/s Ethernet per port.
  
NOT a PCIe x16 card. The MCX621102 series uses a PCIe 4.0 x8 edge connector; the x16 sibling series is MCX623102.
  
NOT an OCP 3.0 or OCP 2.0 mezzanine card. Standard stand-up PCIe form factor.
  
NOT a guaranteed crypto configuration. In the ConnectX-6 Dx 25GbE series, crypto and Secure Boot vary by OPN suffix (AN = no crypto, AC = Crypto + Secure Boot, AE = Crypto only). If crypto offload is a requirement, confirm the exact configuration with T.E.S IT-SOLUTIONS before purchase.
  
NOT supplied with transceivers, cables, or installation accessories.

Compatibility & Hard Constraints

  
Typical switch platforms: NVIDIA Spectrum-family Ethernet switches and other 25GbE SFP28 switch ports, via SFP28 DAC, AOC, or optical links.
  
Software dependencies:
    

      
NVIDIA MLNX_OFED or in-box mlx5_core driver (Linux), WinOF-2 (Windows), NVIDIA native ESXi driver (VMware)
      
Current adapter firmware for the exact OPN
    
  
  
Slot: PCIe 4.0 x8 recommended; operates in PCIe 3.0 slots with reduced host bandwidth headroom.
  
Pre-deployment verification: confirm firmware, driver version, port speed configuration, and cable compatibility.

Frequently Asked Questions (FAQ)
Q. What is the NVIDIA Mellanox MCX621102A-ADAT?
It is a ConnectX-6 Dx EN Ethernet adapter with two SFP28 ports at up to 25Gb/s Ethernet each and a PCIe 4.0 x8 host interface, in a stand-up HHHL PCIe form factor with tall bracket.
Q. What connector form factor does the MCX621102A-ADAT use?
SFP28. Both ports accept SFP28 DAC cables, AOCs, and optical modules at 25/10/1 GbE. QSFP-family cables and modules are not compatible.
Q. Is the MCX621102A-ADAT a PCIe x8 or x16 card?
PCIe 4.0 x8. The related MCX623102 series provides the same 25GbE dual-port SFP28 configuration with a PCIe 4.0 x16 interface.
Q. Does the MCX621102A-ADAT include crypto and Secure Boot?
Crypto and Secure Boot configuration in the ConnectX-6 Dx 25GbE series depends on the OPN suffix (AN, AC, or AE). Confirm the required security configuration with T.E.S IT-SOLUTIONS before deployment if crypto offload matters for your use case.
Q. What switches and cables work with the MCX621102A-ADAT?
Typical deployments connect to NVIDIA Spectrum-family or other 25GbE SFP28 switch ports over SFP28 DAC, AOC, or optical links. Verify firmware, driver, and cable compatibility before deployment.
Q. What condition is supplied by T.E.S IT-SOLUTIONS?
Refurbished. Each unit is bench-tested where test topology is available — link verification, vendor data check, and cosmetic inspection. EU stock, global B2B shipping.
Why T.E.S IT-SOLUTIONS
Every MCX621102A-ADAT unit ships with: (1) link verification where test topology is available, (2) EEPROM / vendor data check, (3) full cosmetic inspection, (4) professional anti-static packaging, (5) global B2B shipping from EU stock, (6) technical consultation for data-center network design at no extra cost.