StarTech.com Dell EMC 3CSFP91 Compatible QSFP+ Module — 40GBASE-ER4

Unlock enterprise-grade performance for your data center with the StarTech.com Dell EMC 3CSFP91 Compatible QSFP+ Module. Specifically designed to deliver high-speed 40 Gigabit Ethernet over single-mode fiber, this QSFP+ transceiver combines reliability, long-range reach, and seamless compatibility with Dell EMC networks. Built to meet rigorous industry standards, it’s the ideal upgrade or expansion solution for core switches, aggregation layers, and spine-leaf architectures that demand predictable, low-latency connectivity across vast distances. Whether you’re optimizing a new deployment or refreshing aging infrastructure, this 40GBASE-ER4 module provides the speed, density, and diagnostic visibility your network demands.

• High-performance 40GBASE-ER4 QSFP+ module — This module supports four 10 Gbps lanes to deliver a combined 40 Gbps data rate, enabling ultra-fast interconnects between switches, routers, and storage systems. Engineered for enterprise data centers, it supports dense, scalable uplinks and long-haul links, making it the dependable backbone for bandwidth-hungry applications, virtualization, and large-scale clustering. The ER4 standard ensures efficient use of optical fiber while maintaining robust performance across demanding traffic patterns.
• Dell EMC 3CSFP91 compatibility — Engineered to align with Dell EMC ecosystems, this StarTech module is designed for plug-and-play integration with Dell EMC switches and routers that rely on 3CSFP91-compliant transceivers. Expect seamless recognition, stable operation, and consistent performance when deployed in Dell-based networks, eliminating compatibility guesswork and reducing deployment time for IT teams.
• Single-Mode Fiber (SMF) reach up to 40 km — Ideal for campus and data-center interconnects, the 40GBASE-ER4 module supports long-reach links over single-mode fiber, enabling reliable interbuilding connections, remote data replication, and disaster recovery topologies. The extended reach helps consolidate data paths, simplify network topologies, and minimize the need for optical amplification across multi-building deployments.
• DDM/DOM for real-time diagnostics — Digital Diagnostics Monitoring (DDM/DOM) provides live optical parameters such as optical transceiver temperature, supply voltage, bias current, and optical power. This visibility enables proactive maintenance, faster fault isolation, and improved uptime by alerting administrators to deviations before they affect service levels. It’s a critical feature for ensuring predictable performance in 24/7 environments.
• Easy installation, reliability, and enterprise-grade durability — As a hot-pluggable QSFP+ module, it slots into standard 4-liber QSFP+ ports with minimal downtime. The robust construction and adherence to industry standards ensure consistent performance across multiple hardware generations, while StarTech’s engineering focus emphasizes reliability, low insertion loss, and long-term operational stability under typical data-center environmental conditions.

Technical Details of StarTech.com Dell EMC 3CSFP91 Compatible QSFP+ Module

• Form factor: QSFP+ (Quad Small Form-factor Pluggable Plus)
• Data rate: 40 Gbps total (4 x 10 Gbps lanes)
• Optical standard: 40GBASE-ER4
• Fiber type: Single-Mode Fiber (SMF)
• Wavelength: 1310 nm (typical for ER4 operation)
• Reach: Up to 40 km (depending on fiber quality and link budget)
• Connector: MPO/MTP-style interface for multi-lane Ethernet optics
• DDM/DOM: Yes, provides real-time optical diagnostics
• Compatibility: Dell EMC 3CSFP91 ecosystem (plug-and-play with compatible devices)
• Power consumption: Designed for efficiency with typical optical module power in the low-watt range
• Operating temperature: 0 to 70 °C (industrial-standard range for data-center equipment)
• Compliance: IEEE 802.3ba 40GBASE-ER4, RoHS compliant

How to Install StarTech.com Dell EMC 3CSFP91 Compatible QSFP+ Module

To install, ensure you have a powered-down device and an available QSFP+ port that supports 40GBASE-ER4 operation. Follow these steps to complete a safe, reliable installation:

Step 1: Power down and prepare the system. Power down the switch, router, or server chassis according to your vendor’s best practices and unplug the device if necessary. Ground yourself to avoid static discharge, and verify that you have a compatible QSFP+ port ready for the new module.

Step 2: Open the DIN cover or tray. Remove the server or switch cover as required to access the QSFP+ port. If your hardware uses a dedicated cage or tray, release the latch and prepare for module insertion.

Step 3: Align and insert the module. Gently align the StarTech QSFP+ module with the slot, ensuring the connector faces the back of the chassis. Insert it straight and firmly until you hear a click indicating proper seating. Do not force the module; if it doesn’t seat smoothly, remove and reinsert to confirm alignment.

Step 4: Verify fiber connections. Attach the single-mode fiber pair to the MPO/MTP interface as specified by your deployment plan. Ensure the correct fiber directionality and polarity are observed to avoid cross-link issues. Handle fiber cables with care to maintain low insertion loss and clean connectors before mating.

Step 5: Power up and validate. Restore power to the device, boot the system, and enter the management interface. Confirm the new transceiver is detected, and review link status, speed, and error counters. If DDM is enabled, monitor live optical parameters to ensure the module operates within expected ranges. In enterprise environments, perform a short traffic test to validate throughput and latency under typical workloads.

Step 6: Monitor and maintain. Enable and monitor the DDM data from the transceiver to catch anomalies early. Plan periodic checks and firmware/driver updates as part of your standard maintenance cycle to sustain long-term performance and reliability.

Frequently asked questions

• What is the purpose of this transceiver? It provides high-speed 40G Ethernet connectivity over single-mode fiber, enabling long-range links between data-center devices while maintaining compatibility with Dell EMC networks via the 3CSFP91 standard.
• Is this module hot-swappable? Yes. The QSFP+ form factor is designed for hot-swapping in supported equipment, minimizing downtime during upgrades or maintenance.
• Does it support diagnostics? Yes, it includes Digital Diagnostics Monitoring (DDM/DOM) to give real-time visibility into temperature, power, and optical performance, helping you detect issues before they affect service levels.
• What is the maximum distance? On single-mode fiber, the ER4 specification supports up to 40 kilometers, depending on fiber quality, connectors, and network design. Always validate reach with your specific fiber plant and link budget.