QSFP-40G-SR4 vs QSFP-40G-SR4-S: Which 40G Transceiver is Right for You?
In today's fast-moving business world, choosing the right network gear can be tough. If you're stuck between the QSFP-40G-SR4 and QSFP-40G-SR4-S transceivers, you're not alone. Both offer high-speed performance, but knowing their differences is key to boosting your network.
This article breaks down these 40G
What are 40G Transceivers?
40G transceivers are optical modules that can transmit and receive data at a rate of 40 gigabits per second. They are designed to work with networking equipment that supports 40G speeds, such as switches, routers, and servers. Common types of 40G transceivers include Cisco QSFP-40G-SR4 and Cisco QSFP-40G-SR4-S.
What is the QSFP-40G-SR4?
The QSFP-40G-SR4 is a Cisco-compatible Quad Small Form-factor Pluggable Plus (QSFP+) optical transceiver module. It is designed to support high-speed 40GBASE-SR4 Ethernet connectivity over short range.
This module operates over a wavelength of 850nm. It is capable of reaching a maximum link distance of 150 meters over OM4 multimode fiber (MMF) or 100 meters over OM3 MMF, making it suitable for short-range data transmission applications.
Specifications of QSFP-40G-SR4:
- Form Factor: QSFP+
- Max Data Rate: 40 Gbps
- Wavelength: 850nm
- Max Cable Distance: 150m@OM4 / 100m@OM3
- Connector: MTP/MPO-12 Male
- Media: MMF
- Transmitter Type: VCSEL (Vertical Cavity Surface Emitting Laser)
- Receiver Type: PIN (Positive-Intrinsic-Negative) photodiode
- TX Power: -7~1dBm
- Receiver Sensitivity: <-9.5dBm
- Power Consumption: <1.5W
- Bit Error Ratio (BER): 1E-12
- Commercial Temperature Range: 0 to 70°C (32 to 158°F)
- Protocols: IEEE 802.3ba, QSFP+ MSA, SFF-8436
Key Features
- Compatibility: Easy to install and replace without interrupting the network, ensuring minimal downtime and maintenance efficiency.
- Versatile Applications: Ideal for use in data centers, campus networks, and various network interconnections, including switches, routers, NICs, and transport equipment. The module supports breakout to 4x10GBASE-SR, providing flexibility for different network configurations.
What is the QSFP-40G-SR4-S?
The QSFP-40G-SR4-S is a high-performance optical transceiver module designed for short-range 40GBASE-SR4 Ethernet applications. Only compatible with Cisco equipment, this QSFP+ module operates at a wavelength of 850nm and supports data rates up to 41.25Gbps, making it ideal for high-speed data center connectivity.
Specifications QSFP-40G-SR4-S:
- Max Data Rate: 40 Gbps
- Wavelength: 850nm
- Max Cable Distance: 150m@OM4 / 100m@OM3
- Connector: MTP/MPO-12 Male
- Media: MMF
- Transmitter Type: VCSEL
- Receiver Type: PIN
- TX Power: -7~1dBm
- Receiver Sensitivity: <-9.5dBm
- Power Consumption: <1.5W
- Bit Error Ratio (BER): 1E-12
- Commercial Temperature Range: 0 to 70°C (32 to 158°F)
- Protocols: IEEE 802.3ba, QSFP+ MSA, SFF-8436
Key Features
The 40GBase-SR4-S transceiver offers several key features that make it an excellent choice for enhancing network performance:
- Compatibility: Compliant with QSFP+ MSA and IEEE 802.3ba standards, it guarantees compatibility with Cisco-Centered networking equipment.
- Versatile Applications: The 40GBase-SR4-S works perfectly with any equipment that supports the QSFP+ interface and the 40GBASE-SR4 standard. This means you can use it with hardware that follows the same standards, making it flexible and easy to integrate into network setups. It's ideal for use in data centers, campus networks, and connecting switches, routers, and network interface cards (NICs) with Cisco-centered equipment.
Major Difference between QSFP-40G-SR4 and QSFP-40G-SR4-S
Connectivity
Cisco QSFP-40G-SR4-S (S-Class): The S-Class module does not support 4x10G breakout mode. This limitation means it is designed solely for high-bandwidth 40G optical links without the capability to split the signal into four separate 10G channels. This can be a significant consideration if your network requires interoperability with lower-speed interfaces or the flexibility to segment the 40G link into multiple 10G links for specific applications.
In contrast, the QSFP-40G-SR4 Cisco module supports 4x10G breakout mode. This functionality allows the module to interoperate with 10GBASE-SR and SFP-10/25G-CSR-S (in 10G mode) interfaces, providing the flexibility to divide a 40G link into four individual 10G links. This capability is particularly useful in network environments where a mix of 40G and 10G connections are needed, offering greater adaptability and scalability.
Versatility
The Cisco 40GBase-SR4 is widely recognized for its compatibility with various high-density, high-performance computing networks, and data centers, making it a versatile choice for large-scale deployments.
On the other hand, the Cisco 40GBase-SR4-S, while similar in many aspects, may offer slight firmware optimizations or vendor-specific features that can enhance performance in certain Cisco-specific environments, potentially making it more versatile within Cisco’s ecosystem.
Which Module Should You Buy? Factors to Consider When Making Your Decision
Choosing the right module depends on specific factors related to your network environment and requirements. Here are some considerations to help you decide between the Cisco QSFP-40G-SR4 and Cisco QSFP-40G-SR4-S:
Cost Considerations:
When comparing the 40GBase-SR4 and 40GBase-SR4-S, the QSFP-40G-SR4-S offers a more budget-friendly option. At CablesandKits, new QSFP-40G-SR4 units are priced at $162.99, refurbished Cisco units at $42.99, and Cisco factory-sealed versions at $139.99. In contrast, the Cisco 40G-SR4-S is typically available at a lower cost, making it a more economical choice if you have all 40Gbase modules in the existing setup.
Network Compatibility:
If you're planning to upgrade to 40G modules, choosing between the S-Class or Non-S-Class variant of 40GBase-SR4 depends entirely on your existing system.
For a high-bandwidth 40G optical link without the need to split signals into 10G channels, the S-Class 40GBase-SR4-S is perfect. It’s efficient and designed specifically for pure 40G connections.
However, if your network runs on 10GBase and you need flexibility, go with the Non-S-Class Cisco 40GBase-SR4 module. It supports a 4x10G breakout mode, allowing it to interoperate with 10GBASE-SR and SFP-10/25G-CSR-S interfaces. This lets you split a 40G link into four individual 10G links, ideal for mixed 40G and 10G environments.
Both options are compatible with Cisco equipment and meet the same standards. Check your network's specific needs to decide which module is the best fit for you.
Future Proofing:
When planning for future network upgrades or expansions, choosing a module that offers better performance or additional features can be more beneficial in the long run.
If your organization is growing, consider the Cisco QSFP-40G-SR4 module. It’s versatile, supporting a 4x10G breakout mode that lets you split a 40G link into four 10G links. This flexibility allows for gradual upgrades without needing to overhaul your entire infrastructure. Although these advanced modules might have a higher upfront cost, they often save money over time by reducing the need for frequent upgrades.
Non-specialized (Non-S-Class) modules, like the QSFP-40G-SR4, are adaptable to various Gigabit Ethernet standards. This versatility makes your network more flexible and able to grow with your business.
By investing in these future-proof options, you ensure that your network remains robust, efficient, and ready for future demands.
Conclusion
In the competitive realm of high-speed networking, choosing the right transceiver is crucial for performance and efficiency. Both the 40G-SR4 and 40G-SR4-S operate at 850nm, support up to 150 meters over OM4 multimode fiber, and offer data rates up to 40Gbps. They comply with QSFP+ MSA and IEEE 802.3ba standards, ensuring compatibility and reliability.
The QSFP-40G-SR4 supports 4x10G breakout mode, making it ideal for environments needing interoperability with 10G interfaces and segmented connections. Its versatility suits dynamic and scalable network designs. The QSFP-40G-SR4-S is designed for straightforward high-bandwidth 40G links without the need for breakout connectivity or FCoE, offering a cost-effective solution for data centers and enterprise networks prioritizing simplicity and efficiency.
Ultimately, your choice should be guided by cost, specific application requirements, and long-term reliability needs, ensuring you select the module that best aligns with your network’s demands and goals.
Additional Learning Center Resources
- "S-Class" Transceivers vs Non "S-Class" Transceivers
- How to Choose the Right Transceiver for Your Network
- Everything you need to know about fiber optic cables
- Choosing the right Cisco Catalyst Switches for your network
- Enhancing Network Security with Cisco ISE (Identity Services Engine)
- All About 100G Transceivers and Uses in Data Centers
- All About Cisco Active Optical Cables
