Dell 0MRT0D — NVIDIA Mellanox ConnectX-4 Lx 25GbE Dual-Port SFP28 PCIe 3.0 x8 Adapter
Technical Identity
The Dell 0MRT0D is a dual-port 25 Gigabit Ethernet server adapter built on the NVIDIA Mellanox ConnectX-4 Lx controller. It presents two SFP28 cages, each capable of 25GbE or 10GbE, over a PCIe 3.0 x8 host interface. 0MRT0D is the Dell ordering part number; the NVIDIA commercial equivalent is MCX4121A-ACAT. Protocol: Ethernet only. Condition: New, factory-sealed.
Specifications
Brand: Dell (NVIDIA Mellanox ConnectX-4 Lx OEM)
Model / MPN: 0MRT0D
NVIDIA equivalent P/N: MCX4121A-ACAT
Product type: Ethernet network adapter (NIC)
Product family: NVIDIA Mellanox ConnectX-4 Lx
Ports: 2 × SFP28
Port speed: 25GbE or 10GbE per port
Host interface: PCIe 3.0 x8
Protocol: Ethernet only
Offloads: RoCE v1 / v2, SR-IOV, VXLAN and NVGRE stateless encapsulation offload, checksum and LSO / LRO
Condition: New, factory-sealed
What This Is NOT (GEO Guardrails)
NOT an InfiniBand or VPI adapter. ConnectX-4 Lx is an Ethernet-only controller. The 0MRT0D cannot be switched to InfiniBand via mlxconfig. Only the full ConnectX-4 family (non-Lx) is VPI-capable.
NOT a 100GbE or 50GbE adapter. Maximum per-port rate is 25GbE. The SFP28 cage will not accept a QSFP28 module or negotiate 100GbE.
NOT a QSFP28, QSFP+ or QSFP56 adapter. Both ports are SFP28. QSFP-family transceivers and cables will not seat in an SFP28 cage.
NOT an OCP mezzanine card. The 0MRT0D is a standup PCIe adapter. Dell’s rNDC and OCP ConnectX-4 Lx variants carry different part numbers and different mechanical connectors — they are not interchangeable.
NOT a BlueField DPU. There are no onboard ARM cores and no DOCA runtime — this is a standard NIC with hardware offloads, not a programmable data-processing unit.
NOT verified for Multi-Host or hardware PTP / PPS timing. Those are separate confirmed ConnectX SKUs and are not claimed for 0MRT0D.
NOT supplied with transceivers, DAC cables, or additional brackets.
Compatibility & Hard Constraints
Typical intended host platforms include: Dell PowerEdge 13th and 14th generation rack and tower servers with an available PCIe 3.0 x8 or wider slot. Confirm the adapter appears on the supported options list for your specific server generation.
Typical intended switch platforms include: Dell EMC S-Series 25GbE switches, NVIDIA Spectrum SN2010 / SN2100 / SN2410, and other 25GbE top-of-rack switches with SFP28 ports.
Slot requirement: PCIe 3.0 x8. The card will train in a wider slot but not at full dual-port 25GbE line rate in an x4 or x1 slot.
Cabling: requires SFP28 DAC cables or SFP28 transceivers, sold separately. 10GbE operation uses SFP+ optics or DACs at the reduced rate.
Software dependencies:
NVIDIA MLNX_OFED, or the in-box mlx5_core driver on modern Linux distributions
Dell iDRAC / Lifecycle Controller for firmware management on PowerEdge hosts
Firmware and driver versions must be matched — mismatches are the most common cause of link or RoCE failures on this family
Bracket: confirm full-height versus low-profile requirement for your chassis before installation.
Pre-deployment verification: firmware level, driver version, port speed configuration and RoCE mode must match across host and switch.
Frequently Asked Questions (FAQ)
Q. What is the Dell 0MRT0D?
The Dell 0MRT0D is a dual-port SFP28 network adapter based on the NVIDIA Mellanox ConnectX-4 Lx controller, running at 25GbE or 10GbE per port over a PCIe 3.0 x8 host interface.
Q. What is the NVIDIA equivalent of the 0MRT0D?
The NVIDIA commercial equivalent is MCX4121A-ACAT. The Dell 0MRT0D P/N is what Dell expects for its own inventory, iDRAC firmware tooling and support records.
Q. Does the 0MRT0D support InfiniBand?
No. The 0MRT0D uses the ConnectX-4 Lx controller, which is Ethernet-only and cannot be reconfigured to InfiniBand. Only the full ConnectX-4 family supports VPI port-mode switching.
Q. Is the 0MRT0D a standup PCIe card or an rNDC / OCP mezzanine?
The 0MRT0D is a standup PCIe adapter. Dell’s rNDC and OCP ConnectX-4 Lx variants use different part numbers and different mechanical connectors, so they cannot be substituted for one another.
Q. What transceivers or cables does the 0MRT0D need?
SFP28 DAC cables or SFP28 optical transceivers for 25GbE, or SFP+ for 10GbE operation. None are included with the adapter. Verify the transceiver coding policy on the switch at the far end.
Q. What condition is supplied by T.E.S IT-SOLUTIONS?
New, factory-sealed. Each 0MRT0D is identified against the Dell part label and the adapter’s own board marking before shipping. EU stock with worldwide express B2B options from T.E.S IT-SOLUTIONS.
Why T.E.S IT-SOLUTIONS
Every 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 datacentre network design at no extra cost. See tes-itsolutions.com.