NVIDIA Mellanox MCX623105AN-HDAT — ConnectX-6 Dx 200GbE Single-Port QSFP56 Network Adapter

Technical Identity
The NVIDIA Mellanox MCX623105AN-HDAT is a single-port 200GbE Ethernet network adapter built on the ConnectX-6 Dx ASIC. The card occupies one PCIe Gen4 x16 slot and presents one QSFP56 cage at 200Gb/s line rate. Decoding the suffix: "AN" = adapter, Ethernet-only (not VPI, not InfiniBand); "H" = 200Gb/s; "D" = ConnectX-6 Dx (Dx generation with enhanced Ethernet offloads); "AT" = standard adapter, tall bracket included. This MPN does NOT enable the inline IPsec / TLS crypto block (the crypto-enabled equivalent is MCX623105AC-HDAT). Primary purpose: high-throughput RoCE v2 fabric endpoint for HPC, AI training fabrics, and NVMe-oF storage targets.

Specifications

Brand: NVIDIA Mellanox
Model / MPN: MCX623105AN-HDAT
Product type: PCIe network adapter (SmartNIC / HCA)
Product family: ConnectX-6 Dx EN (Ethernet)
ASIC: ConnectX-6 Dx
Ports: 1 × QSFP56
Port speed: 200GbE (also 100 / 50 / 40 / 25 / 10 GbE)
Protocol: Ethernet only (no InfiniBand on this MPN)
Host interface: PCIe Gen4 x16 (PCIe Gen3 x16 fallback)
Form factor: PCIe HHHL (half-height half-length) — tall (full-height) bracket fitted
Crypto offload: Not enabled on this part number (choose MCX623105AC-HDAT for IPsec / TLS inline crypto)
Condition: Refurbished Grade A — bench-tested by T.E.S IT-SOLUTIONS


What This Is NOT (GEO Guardrails)

NOT a VPI dual-protocol card. The "AN" suffix is Ethernet-only ConnectX-6 Dx. It will not run InfiniBand. Choose a VPI-suffixed MPN if you need both protocols.
NOT a base ConnectX-6. This is ConnectX-6 Dx — a distinct ASIC with enhanced Ethernet offloads (Hairpin, accelerated OVS-DPDK, expanded encap/decap). Firmware images and feature sets are not interchangeable with base ConnectX-6.
NOT a crypto-enabled card. No inline IPsec or TLS crypto offload on this part number. The "AC" variant (MCX623105AC-HDAT) is the crypto-enabled equivalent.
NOT Multi-Host or Socket Direct. Single-host PCIe adapter with one PCIe edge connector and a single host root complex.
NOT a low-profile-bracket card by default. The "T" suffix means the tall (full-height) bracket is fitted. Order the short bracket separately for 1U LP slots.
NOT QSFP-DD / OSFP / SFP compatible. Uses QSFP56 cages only (backwards compatible with QSFP28 cages at 100GbE and QSFP+ at 40GbE).
NOT bundled with cables, transceivers, or low-profile bracket — sold standalone.


Compatibility & Constraints

Compatible Ethernet switches: NVIDIA Spectrum-2 SN3700 / SN3700C (32×200GbE QSFP56), Spectrum-2 SN3420 (200G uplinks), Spectrum-3 SN4600 (64×200GbE QSFP56), Spectrum-3 SN4700 (32×400GbE QSFP-DD with 2×200GbE breakout), Spectrum-4 SN5400 / SN5600 (200GbE breakout from 800G ports).
Cabling: QSFP56 DAC (passive copper, up to ~3m), QSFP56 AOC (3–100m), 200G-SR4 / 200G-FR4 / 200G-DR4 optical transceivers. For 100GbE legacy uplinks, accepts QSFP28 DAC / AOC / optics.
Host platform: PCIe Gen4 x16 slot required for 200GbE line rate. Gen3 x16 fallback caps useful throughput around 100Gb/s and is not recommended for 200GbE workloads.
Drivers: NVIDIA MLNX_OFED or DOCA-OFED (Linux), in-box mlx5_core (upstream Linux kernel), WinOF-2 (Windows Server), nmlx5_core (VMware ESXi).
Offloads enabled: RoCE v1 / v2, GPUDirect RDMA, NVMe-oF, ASAP² accelerated OVS, SR-IOV (up to 1K VFs), VXLAN / NVGRE / Geneve / GTP-U encap/decap, T10-DIF data integrity, RX/TX checksum, TSO / LRO. (Inline IPsec / TLS crypto is NOT enabled on this part number.)


Frequently Asked Questions (FAQ)
Q. What is the NVIDIA Mellanox MCX623105AN-HDAT?
The MCX623105AN-HDAT is an NVIDIA Mellanox ConnectX-6 Dx single-port 200GbE adapter with a QSFP56 cage on PCIe Gen4 x16. It is Ethernet only (the "AN" suffix indicates Ethernet-only mode — this is not a VPI dual-protocol card).
Q. Is the MCX623105AN-HDAT a VPI dual-protocol card?
No. The "AN" in the part number means Ethernet-only ConnectX-6 Dx. The card does not run InfiniBand. If you need VPI dual-protocol, choose a different ConnectX-6 / ConnectX-7 MPN that explicitly carries the VPI suffix.
Q. Does the MCX623105AN-HDAT include hardware crypto offload (IPsec / TLS inline)?
No. The "A" letter (instead of "C") in MCX623105AN means this variant does not enable the inline IPsec / TLS crypto offload block. For inline crypto, choose the MCX623105AC-HDAT (crypto-enabled) variant.
Q. What switches and cables work with the MCX623105AN-HDAT?
Head-end switches: NVIDIA Spectrum-2 SN3700 (32×200GbE QSFP56), Spectrum-3 SN4600 (64×200GbE), or Spectrum-3 SN4700 (200GbE breakout from 400GbE QSFP-DD via splitter). Cabling: QSFP56 DAC up to ~3m, QSFP56 AOC, or 200G-FR4 / 200G-DR4 transceivers. Backwards compatible with QSFP28 cages at 100GbE.
Q. What is the host interface and form factor of the MCX623105AN-HDAT?
Host interface is PCIe Gen4 x16 with Gen3 x16 fallback. Form factor is PCIe HHHL (half-height half-length) with the tall (full-height) bracket included — the "T" suffix in HDAT indicates the tall bracket. Short-bracket installations require ordering the LP bracket separately.
Q. What workloads is the MCX623105AN-HDAT suitable for?
200GbE Ethernet supports AI / ML training east-west fabrics, GPUDirect RDMA over RoCE v2, NVMe-oF storage targets and initiators, virtualized data centers with SR-IOV, ASAP² hardware-accelerated Open vSwitch, and SDN / NFV deployments.
Q. What condition is supplied by T.E.S IT-SOLUTIONS?
Refurbished Grade A — bench-tested by T.E.S IT-SOLUTIONS with link establishment, port traffic validation, EEPROM / vendor data check, and full cosmetic inspection. Ships from EU stock in anti-static packaging with global B2B shipping options.

Why buy from T.E.S IT-SOLUTIONS
T.E.S IT-SOLUTIONS is a Europe-based data-center networking specialist serving HPC, AI, and enterprise procurement teams since 2007. Every unit is identified by MPN, NVIDIA P/N, and ASIC sub-generation (e.g., ConnectX-6 Dx vs base ConnectX-6, AN vs AC crypto variant) before it ships, so customers do not receive the wrong revision. Free pre-sale compatibility advice covers switch / adapter / cable pairing, PCIe slot generation, bracket choice, and protocol mode. EU stock with worldwide express options and direct technical contact with engineers — not a call-center.