G4MV3 Dell 25GbE 2 Ports SFP28 PCI-E ConnectX-5 Network Adapter

Dell G4MV3 ConnectX-5 EN 25GbE Network Adapter

The Dell G4MV3 ConnectX-5 EN is a high-performance, dual-port Ethernet network interface card (NIC) engineered to deliver exceptional throughput, ultra-low latency, and advanced networking capabilities for modern data centers, high-performance computing (HPC) clusters, and enterprise server environments. Built upon the Mellanox ConnectX-5 EN controller IC, this adapter represents a significant leap forward from previous generations, offering 25 gigabits per second (GbE) per port while maintaining compatibility with lower-speed networks. The card is designed to alleviate network bottlenecks, enabling faster data access, improved application responsiveness, and more efficient server consolidation.

Key Specifications and Features

This network adapter is architected to meet the rigorous demands of next-generation infrastructure. It provides a robust feature set that includes hardware-offloaded virtualization, advanced RoCE (RDMA over Converged Ethernet) for efficient data movement, and sophisticated quality of service (QoS) controls. The integration of these technologies directly into the hardware ensures that performance is not only high but also consistent and reliable, reducing the load on the host CPU and increasing overall system efficiency.

Form Factor

The Dell G4MV3 ConnectX-5 adapter is designed with a standard PCI Express 3.0 x16 form factor, ensuring broad compatibility with a wide range of server platforms. The x16 electrical interface provides ample bandwidth to fully saturate both 25GbE ports simultaneously without becoming a bottleneck. The card features two SFP28 (Small Form-factor Pluggable 28) cages, which are designed to support both 25GbE and 10GbE connections using the appropriate SFP28 or SFP+ optical transceivers or Direct Attach Copper (DAC) cables. This flexibility allows for seamless integration into existing 10GbE infrastructure while providing a clear, cost-effective migration path to 25GbE performance.

PCI Express Bus Compatibility

While the card utilizes a PCIe 3.0 x16 connector, it maintains backward compatibility with PCIe 3.0 x8 slots, though this may impact the maximum achievable throughput. It is also forward-compatible with PCIe 4.0 systems, operating at the host system's capable speed. This ensures investment protection and flexibility across multiple server generations.

Performance and Throughput Capabilities

The primary advantage of the 25GbE standard is its ability to deliver 2.5 times the bandwidth of standard 10GbE networking on a single lane, maximizing the efficiency of the underlying switch infrastructure and server port count. The Dell G4MV3 ConnectX-5 EN is meticulously engineered to harness this potential, delivering line-rate, full-duplex throughput on both ports concurrently. This translates to a staggering aggregate bandwidth of 50 Gbps, making it an ideal solution for data-intensive applications, large-scale storage access, and virtualized environments where network I/O is a critical performance factor.

Ultra-Low Latency

Beyond raw bandwidth, latency is a crucial metric for many performance-sensitive applications. The ConnectX-5 EN chipset is renowned for its ultra-low latency processing, which significantly reduces the time it takes for a data packet to travel from the network to the application. This is achieved through a highly optimized data path and efficient protocol processing within the network controller itself. For applications such as financial trading, real-time analytics, and clustered databases, shaving off microseconds can lead to substantial improvements in overall transaction times and user experience.

CPU Offload Engine Technology

A cornerstone of the ConnectX-5 architecture is its comprehensive suite of hardware offloads. By handling complex networking tasks directly on the adapter, it frees up the server's central processing units (CPUs) to focus on application workloads. This results in higher overall system performance, improved power efficiency, and the ability to support a greater number of virtual machines or containers per server.

Checksum and Segmentation Offloads

The adapter performs TCP/UDP checksum calculation and validation in hardware, ensuring data integrity without CPU cycles. It also supports Large Send Offload (LSO) and Receive Side Scaling (RSS), which optimize the transmission and reception of large data packets across multiple CPU cores.

VXLAN and NVGRE Offloads

For modern overlay networks common in cloud and virtualized environments, the card provides hardware offloads for VXLAN and NVGRE encapsulation and decapsulation. This eliminates the performance penalty typically associated with software-based network virtualization, allowing these advanced networking features to be used at full line rate.

Advanced Networking Technologies and Protocols

The Dell G4MV3 ConnectX-5 EN is more than just a simple network interface; it is a sophisticated networking platform that supports a suite of advanced protocols designed to increase efficiency, reduce latency, and enable new architectural paradigms like disaggregated storage and HPC.

RDMA over Converged Ethernet (RoCE)

One of the most significant features of this adapter is its native support for RDMA over Converged Ethernet, specifically RoCE v2. RDMA (Remote Direct Memory Access) allows one computer to directly access the memory of another without involving the operating system or CPU of either machine. This enables "kernel bypass," dramatically lowering latency and CPU utilization for network-intensive tasks. RoCE v2 extends this capability over standard IP-based Layer 3 networks, making it practical for deployment in mainstream data centers. This technology is fundamental for technologies like Storage Spaces Direct (S2D), hyper-converged infrastructure (HCI), and AI/ML training clusters.

Benefits of RoCE in Storage and HPC

In storage applications, RoCE allows for extremely fast access to network-attached storage (NAS) or storage area networks (SAN), making the network feel like a local bus. In HPC, it facilitates rapid data exchange between nodes in a cluster, which is essential for parallel processing workloads. The efficiency gains from RoCE can often double the effective performance of the network compared to traditional TCP/IP-based communication.

SR-IOV (Single Root I/O Virtualization)

For virtualized server environments, the Dell G4MV3 ConnectX-5 EN supports SR-IOV, a standard that allows a single physical adapter to present itself as multiple virtual functions (VFs) to the hypervisor. Each virtual function can be assigned directly to a virtual machine (VM), providing the VM with near-native network performance. This bypasses the virtual switch in the hypervisor, resulting in significantly lower latency, higher throughput, and reduced CPU overhead compared to traditional para-virtualized or emulated NICs. This capability is critical for hosting demanding, latency-sensitive applications within VMs.

Implementation in Hyper-V and VMware Environments

The adapter is fully compatible with SR-IOV implementations in major hypervisors like VMware vSphere and Microsoft Hyper-V. When configured, it allows network administrators to achieve much higher VM density per host while maintaining strict performance isolation and service-level agreements (SLAs) for each virtual machine.

Network Infrastructure Integration

To leverage the full 25GbE capability of this adapter, the network switching infrastructure must also support 25GbE. The adapter's SFP28 ports are compatible with a wide range of SFP28 optical transceivers (e.g., SR, LRM, LR) for fiber optic cabling, as well as SFP28 Direct Attach Copper (DAC) cables for short-reach, cost-effective connections to top-of-rack (ToR) switches. Furthermore, the ports are fully backward compatible with 10GbE SFP+ transceivers and DAC cables, providing a flexible and non-disruptive upgrade path. Many 25GbE switches also support 10/25GbE auto-negotiation, allowing the adapter to automatically connect at the highest mutually supported speed.

Cabling and Transceiver Options

Choosing the correct cabling is essential for a successful deployment. For distances up to 100 meters over multi-mode fiber (OM3/OM4), SFP28 SR (Short Range) transceivers are ideal. For longer distances up to 10 kilometers, LR (Long Range) transceivers over single-mode fiber are used. For in-rack connections (typically under 5 meters), passive or active SFP28 DAC cables offer a simple, low-power, and low-latency solution.

Use Cases

The performance characteristics of the Dell G4MV3 ConnectX-5 EN make it exceptionally well-suited for specific high-demand workloads and IT architectures where network performance is a critical bottleneck.

Hyper-Converged Infrastructure (HCI)

In HCI platforms like VMware vSAN or Microsoft Storage Spaces Direct, the network is the storage backplane. The high bandwidth and ultra-low latency provided by this adapter, especially when combined with RoCE, are essential for ensuring fast storage reads and writes across the cluster. This directly impacts VM performance and the overall responsiveness of applications running on the HCI platform.

High-Performance Computing and AI/ML Clusters

Clusters used for scientific research, engineering simulations, and artificial intelligence/machine learning training require immense amounts of inter-node communication. The low-latency RDMA capabilities of the ConnectX-5 adapter drastically reduce the time nodes spend waiting for data, accelerating time-to-solution for complex computational problems.

High-Frequency Trading and Real-Time Analytics

In financial services and other industries where microseconds matter, the predictable, ultra-low latency of this network card is a non-negotiable requirement. It ensures that market data and transaction messages are processed and transmitted with the absolute minimum delay.

Virtualized Data Centers and Cloud Platforms

For large-scale virtualization and cloud hosting providers, the combination of high throughput, SR-IOV, and CPU offloads allows for greater server consolidation ratios. This means more VMs can be hosted on a single physical server without compromising network performance.