HPE / NVIDIA Mellanox 817751-001 — 10/25GbE Dual-Port SFP28 Network Adapter (ConnectX-4 Lx)

Technical Identity
The 817751-001 is HPE's option / spare part number for the HPE Ethernet 10/25Gb 2-port 640SFP28 Adapter, an OEM build of the NVIDIA Mellanox ConnectX-4 Lx Ethernet network adapter silicon (MCX4121A-ACAT class). It is a low-profile, half-length PCIe 3.0 ×8 server adapter card with two SFP28 cages driven by the ConnectX-4 Lx ASIC, supplying line-rate 25 Gigabit Ethernet per port with full backward auto-negotiation to 10 GbE and 1 GbE. The card is HPE-keyed (HPE Smart-Component firmware envelope, HPE iLO recognition, HPE 640SFP28 product family) and is supplied by T.E.S IT-SOLUTIONS as a refurbished Grade A unit, bench-tested for PCIe enumeration, dual-port link training, and signal integrity prior to shipment.

Specifications

OEM Brand: HPE (HPE option / spare part)
Silicon: NVIDIA Mellanox ConnectX-4 Lx (Ethernet only, Lx ASIC)
HPE Part Number (MPN): 817751-001
HPE Product Name: HPE Ethernet 10/25Gb 2-port 640SFP28 Adapter
Form Factor: PCIe low-profile, half-length adapter card
Host Interface: PCI Express 3.0 ×8 (8.0 GT/s per lane)
Ports: 2 × SFP28
Port Speeds: 25 GbE / 10 GbE / 1 GbE (auto-negotiated)
Protocol Support: Ethernet only (Lx ASIC — not VPI, no InfiniBand mode)
RDMA: RoCE v1 and RoCE v2 (RDMA over Converged Ethernet)
Storage Offload: NVMe-oF over RoCE v2, T10-DIF data-integrity offload
Virtualization: SR-IOV (up to 128 VFs per port), ASAP² eSwitch / OVS offload
Tunneling Offload: VXLAN, NVGRE, Geneve, GTP encap / decap
Condition: Refurbished Grade A — bench-tested by T.E.S IT-SOLUTIONS


What This Is NOT
The 817751-001 is not a 40 GbE, 50 GbE, or 100 GbE adapter — the SFP28 cages and the ConnectX-4 Lx ASIC cap each port at 25 GbE. It is not a QSFP / QSFP28 card; the connectors are SFP28 (single-lane) and will not accept QSFP-form-factor optics or DACs. It is not a VPI dual-protocol card — ConnectX-4 Lx is Ethernet only (Lx ASIC) and does not support InfiniBand FDR / EDR mode (only the full ConnectX-4 VPI variants do that, and they carry different HPE / Mellanox part numbers). It is not a switch, transceiver, or cable; it requires a host PCIe 3.0 ×8 (or wider) slot and is supplied without bundled SFP28 optics, DACs, AOCs, or additional low-profile bracket inventory beyond the bracket already fitted to the card.

Compatibility & Constraints
The 817751-001 is HPE-qualified for HPE ProLiant Gen9 and Gen10 rack and tower servers (DL360 / DL380 / DL580 Gen9–Gen10, ML350 Gen9–Gen10) and HPE Apollo systems with PCIe 3.0 ×8 or wider slots; it is also functional in standard non-HPE servers, but HPE Smart-Component firmware tooling and iLO recognition require an HPE host. On the wire it pairs with NVIDIA Spectrum / Spectrum-2 Ethernet switches (SN2010, SN2100, SN2410, SN2700, SN3700, SN3420), HPE FlexFabric / Aruba 25GbE switches, and any IEEE 802.3by 25GbE switch via passive copper DAC (SFP28 DAC, up to ~3 m), active optical cable (SFP28 AOC, up to ~30 m), or transceiver plus LC fiber (SR / LR optics). Software-side it is driven by NVIDIA MLNX_OFED and the inbox upstream-Linux mlx5_core driver, WinOF-2 on Windows Server, and nmlx5 on VMware ESXi. RoCE v2 requires a PFC / DCB-capable switch fabric for lossless behavior.

Frequently Asked Questions (FAQ)
Q. Is the 817751-001 an InfiniBand card?
No. The 817751-001 is built on the NVIDIA Mellanox ConnectX-4 Lx silicon, which is an Ethernet-only ASIC. It does not support InfiniBand FDR, EDR, or HDR. Only full ConnectX-4 VPI variants (different part numbers) carry InfiniBand support.
Q. What is the maximum line rate per port?
Each SFP28 port runs at line-rate 25 GbE and auto-negotiates down to 10 GbE or 1 GbE depending on the link partner. The card cannot be aggregated into a single 50 GbE port — that would require QSFP+ / QSFP28 form factor, which this card does not have.
Q. Will the 817751-001 work in a non-HPE server?
Yes. Electrically and functionally it is a standard PCIe 3.0 x8 ConnectX-4 Lx adapter and will enumerate in any server with a compatible slot using NVIDIA MLNX_OFED or the inbox mlx5_core driver. HPE-specific tooling (Smart-Component firmware packages, iLO health reporting) only operates on HPE hosts.
Q. What condition is the 817751-001 supplied in by T.E.S IT-SOLUTIONS?
The card ships as refurbished Grade A — bench-tested by T.E.S IT-SOLUTIONS for PCIe enumeration, dual-port link establishment at 25 GbE, and signal-integrity / loopback verification, in anti-static packaging from EU stock.

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 refurbished 25 GbE adapter is bench-tested against matched SFP28 fabric — both ports trained, both ports traffic-validated, EEPROM read confirmed for HPE option keying — before it leaves our facility. Pre-sale technical consultation on HPE ProLiant compatibility, RoCE v2 fabric tuning, MLNX_OFED versus inbox driver decisions, and mixed 10/25 GbE migration paths is available directly with our engineering team. Multi-currency B2B invoicing, anti-static packaging, EU stock with worldwide DHL / FedEx / UPS dispatch.