Dell Mellanox ConnectX-4 LX 25GbE CX4121C Dual Port Network Adapter

Overview

The Dell MRT0D is a dual port network adapter featuring the Mellanox ConnectX-4 LX controller, designed to deliver two 25 gigabit Ethernet connections via SFP28 interfaces. It fits into a PCI Express Gen3 x8 slot, providing high bandwidth without occupying a full x16 lane. This adapter is optimized for environments where low latency and efficient CPU usage are critical, such as virtualized servers, cloud nodes, and high performance computing clusters.

By offloading VXLAN and NVGRE tunneling to onboard hardware engines, it reduces host processor overhead and maintains steady network performance even under heavy east-west traffic loads. This makes it a strong choice for data centers and enterprises aiming to boost throughput for storage, VM migration, and clustered applications without major infrastructure changes.

Key features

• Two 25 gigabit Ethernet ports supporting both SFP28 optical modules and direct-attach cables for flexible connectivity options
• PCI Express Gen3 x8 interface that balances high data transfer rates with efficient slot usage
• Hardware offload engines for VXLAN and NVGRE tunneling that reduce CPU load and improve network efficiency
• Consistent low latency performance that supports demanding workloads and minimizes bottlenecks
• Engineered for enterprise data centers, private and public cloud environments, and high performance computing clusters requiring reliable, high-speed networking

Key specs

• Network ports: 2 x 25 GbE via SFP28
• Host interface: PCI Express Gen3 x8
• Offload support: VXLAN and NVGRE tunneling
• Latency: optimized for low microsecond-level latency
• Compatibility: fits in Dell PowerEdge servers and other PCIe Gen3 systems

Connectivity and compatibility

This adapter supports SFP28 optical transceivers and direct-attach copper cables, allowing flexible deployment in various network infrastructures. Its PCIe Gen3 x8 slot compatibility ensures it can be installed in a wide range of servers, including Dell PowerEdge models, without requiring proprietary connectors or occupying excessive slot space.

• Supports SFP28 modules for fiber optic connections
• Compatible with direct-attach copper cables for short-range links
• Works with standard PCI Express Gen3 x8 slots for broad server compatibility

Performance and reliability

The onboard hardware offload engines handle overlay network protocols, which significantly reduces CPU utilization during heavy network traffic. This leads to more predictable and stable performance, especially in virtualized and cloud environments where east-west traffic is common. The adapter’s design supports continuous operation in demanding data center conditions, ensuring reliable connectivity for critical workloads.

Ideal uses and environments

This network adapter is well suited to enterprise data centers and private or public cloud deployments that require fast, low-latency connections between servers. It excels in setups with dense virtualization, data-intensive analytics, or clustered applications where high throughput and efficient CPU usage are essential. Organizations looking to upgrade their network infrastructure without overhauling their entire platform will find this adapter a practical and effective solution.