540-BCOT: Dell Mellanox ConnectX-5 Dual Port 25GbE SFP28 OCP 3.0 Adapter

Also listed as: 08N89F, 8N89F, MCX562A-ACAI · made by NVIDIA

The Dell 540-BCOT is a Dell Mellanox ConnectX-5 Dual Port 25GbE SFP28 OCP 3.0 Adapter delivering 25GbE network connectivity across 2x 25GbE SFP28 via PCIe 3.0 x16 OCP 3.0 SFF. Built with NVIDIA controller architecture, the 540-BCOT provides hardware offload acceleration and virtualization support for R740, R640, R750, R650 enterprise servers.

Specifications

About the 540-BCOT

The Dell 540-BCOT is a Dell Mellanox ConnectX-5 Dual Port 25GbE SFP28 OCP 3.0 Adapter engineered to deliver 25GbE network transmission across 2x 25GbE SFP28 over PCIe 3.0 x16 OCP 3.0 SFF. Powered by NVIDIA controller architecture on the 540-BCOT, it executes hardware-level protocol processing, RoCE, and SR-IOV virtualization while maintaining a thermal envelope of approximately 14W. In Dell's networking portfolio, 540-BCOT provides dedicated high-bandwidth fabric connectivity for clustered virtualization, network storage, and enterprise database hosts.

Compatibility

Engineered for Dell PowerEdge servers including R740, R640, R750, R650, the 540-BCOT mounts directly into OCP 3.0 Small Form Factor locations. The 540-BCOT slides into the rear OCP 3.0 mezzanine bay with an ejection latch, preserving PCIe riser slots. Cabling the 540-BCOT requires 25GbE-rated media, including direct attach copper twinaxial assemblies, optical transceivers, or patch leads matched to its physical ports. Supported operating systems on the 540-BCOT include VMware ESXi, Red Hat Enterprise Linux, and Windows Server with native Dell drivers.

How to identify a genuine unit

Authentic Dell 540-BCOT units carry an identification label displaying DP/N 08N89F and NVIDIA model code MCX562A-ACAI along with Dell regulatory marks. In iDRAC Network Devices inventory, the card registers under part number 540-BCOT with active link state, port MAC addresses, negotiated speed, and certified Dell firmware. Onboard physical indicators on the 540-BCOT provide link status and port activity monitoring.

Buying used

When purchasing a pre-owned 540-BCOT, examine the gold edge connector fingers for scratches, peeling contacts, or missing surface-mount capacitors. Ensure that the 540-BCOT OCP pull-latch mechanism is intact and properly aligned for chassis installation. Validate in iDRAC Lifecycle Controller that the 540-BCOT is recognized with certified Dell firmware and passes diagnostics under sustained 25GbE network traffic.

Fits these models

• Dell PowerEdge R740
• Dell PowerEdge R640
• Dell PowerEdge R750
• Dell PowerEdge R650
• Dell PowerEdge R760
• Dell PowerEdge R660

Works together

How the Dell 540-BCOT connects to servers, storage and the network: 3 ways, with the hardware on each path.

Plan and size it

• Draw this setup in the topology planner mrplanb.com
• Add up rack power and space rack-density.com
• iSCSI explained mrplanb.com
• Virtualization storage Ledger: scored storage platforms mrplanb.com
• Network monitoring tools compared mrplanb.com
• Dell E-Lab Navigator (Dell interoperability) dell.com

Equivalent part numbers

• NVIDIA MCX562A-ACAI NVIDIA Mellanox ConnectX-5 EN 25GbE Dual-Port SFP28 OCP 3.0 OEM base

FAQ

Sources

• Dell Mellanox ConnectX-5 Dual Port 25GbE OCP 3.0 Adapter Specifications, checked 2026-10-27