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Green circuit board with two silver SFP28 cages and a tall metal bracket

Mellanox Technologies

Mellanox Technologies MCX512F-ACAT 25GbE dual-port SFP28 PCIe 3.0 x16 network card

SKU CH-KY09-CX31Z MPN MCX512F-ACAT

Dual-port 25GbE SFP28 adapter with PCIe 3.0 x16 interface for high-throughput cloud and storage workloads

  • Rated speed25GBase-X
  • Interface typePCI-Express
  • Connection types25GBase-X
  • Bus interfacePCI Express 3.0 x16
  • Product classPCI Express
  • Product weight0.39
  • Dual 25 GbE ports for high-throughput networking
  • PCIe 3.0 x16 interface delivers 16 lanes of bandwidth
  • RDMA offload cuts CPU load for storage workloads
  • NVMe over Fabric target offload accelerates data-path processing
  • Tall bracket fits standard server chassis

Dual-port 25GbE SFP28 adapter

The Mellanox ConnectX-5 EN card delivers two 25GbE ports over a PCIe 3.0 x16 interface. It targets cloud, storage and telco platforms that need RDMA and advanced offloads in a standard add-in form factor.

Sustained throughput and latency

Hardware offloads such as T10-DIF signature handover and NVMe over Fabric target acceleration keep CPU utilisation low during continuous storage traffic. Open vSwitch offload and DPDK support maintain high packet rates without thermal throttling on the tall bracket design.

Compatibility checks

Verify the host provides a PCIe 3.0 x16 slot and sufficient bracket height for the tall bracket. Ensure SFP28 modules and 25GBase-X cabling match the intended link speed and reach.

How it compares

Measured against everything we stock in Ethernet Cards & NICs, at today’s prices. Recalculated every night.

Price $410.99
Pricier than about 83% of the 1,505 comparable items (median $90.99).

Specifications

Product
Brand nameMellanox
Product classPCI Express
Performance
Rated speed25GBase-X
Ports & slots
Interface typePCI-Express
Connection types25GBase-X
Bus interfacePCI Express 3.0 x16
Size & build
Shipping weight0.68 kg
Package size254 × 152 × 25 mm

Questions about this item

How much heat does the 25GbE dual-port SFP28 card add to a chassis running all day?

The card draws power through a PCIe 3.0 x16 slot and uses a passive heatsink; no active fan is fitted, so thermal load is modest and scales with 25GbE traffic.

What cabling and switch ports must I already own for the MCX512F-ACAT to link up?

You need two 25GBase-X SFP28 transceivers and matching fibre or DAC cables, plus a switch that provides 25GbE SFP28 ports.

Will the PCIe 3.0 x16 interface bottleneck the ConnectX-5 adapter in a server that only has Gen 3 slots?

The adapter operates at PCIe 3.0 x16, matching the slot, so 25GbE line-rate on both ports is sustained without Gen 4 bandwidth.

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