400G QSFP112 SR4 and DR4 Transceivers for NVIDIA AI, InfiniBand and Ethernet Networks

As AI clusters, GPU servers, HPC platforms and cloud data centers move rapidly toward 400G connectivity, the demand for compact, high-speed and low-latency optical interconnects continues to grow. QSFP112 is an advanced evolution of the QSFP form factor, designed to support 112Gb/s per lane in a four-lane QSFP system, enabling a 400G interconnect ecosystem for next-generation data centers. The QSFP112 MSA describes QSFP112 as a module and cage/connector system based on the current QSFP architecture, targeting 112Gb/s per lane in a 4-lane QSFP system.

Optech offers high-performance 400G QSFP112 transceiver solutions, including 400G QSFP112 SR4 and 400G QSFP112 DR4, designed for AI computing, high-speed Ethernet, InfiniBand, GPU interconnects and data center networking. These modules are developed to support demanding NVIDIA-based environments, including deployments using NVIDIA ConnectX-7 and BlueField-3 platforms, where 400G QSFP112 connectivity is required on the adapter or DPU side. NVIDIA’s own documentation lists ConnectX-7 and BlueField-3 platforms with QSFP112 interfaces, including 400Gb/s InfiniBand and 400GbE configurations.

What Is QSFP112?

QSFP112 is a compact four-lane pluggable form factor engineered for 100G-PAM4 electrical signaling per lane, enabling 400G aggregate bandwidth in a QSFP-style module. Compared with earlier QSFP28 or QSFP56 generations, QSFP112 allows data centers to increase bandwidth density while maintaining a familiar QSFP-based deployment model.

For legacy QSFP users, QSFP112 provides an efficient upgrade path toward 400G per port. This is especially valuable for data centers that want higher port bandwidth without moving entirely to larger or different form factors in every part of the network.

Optech 400G QSFP112 Transceiver Portfolio

NVIDIA’s 400G 100G-PAM4 interconnect guide describes SR4 as a 400G four-channel multimode option up to 50 meters and DR4 as a 400G four-channel single-mode option with 100-meter and 500-meter reach classes. It also notes that 400G QSFP112 is used in ConnectX-7/QSFP112 and BlueField-3/QSFP112 environments rather than switch cages.

Designed for InfiniBand and Ethernet AI Networks

Optech 400G QSFP112 SR4 and DR4 transceivers are suitable for both InfiniBand and Ethernet network architectures. This makes them ideal for AI training clusters, GPU-to-switch interconnects, high-performance computing, large-scale data center fabrics and cloud infrastructure.

NVIDIA documentation explains that LinkX cables and transceivers, ConnectX-7 network adapters and BlueField-3 DPUs can contain both InfiniBand and Ethernet firmware and can support the protocol used by the connected switch in 100G-PAM4 product lines.

For AI workloads, 400G connectivity is especially important because large GPU clusters require fast east-west traffic, low latency, high bandwidth and stable signal integrity. Optech’s 400G QSFP112 modules help support high-throughput communication between GPU servers, DPUs, NICs and high-speed switches.

NVIDIA-Compatible 400G QSFP112 Connectivity

In NVIDIA AI networking environments, 400G QSFP112 transceivers are commonly used on adapter-side or DPU-side connections such as ConnectX-7/QSFP112 and BlueField-3/QSFP112 platforms. For switch-side connections, NVIDIA 400G systems may use OSFP or twin-port OSFP architectures, so the correct optical module type and cable architecture must be selected for each side of the link. NVIDIA’s guide states that QSFP112 cannot be used in OSFP switches and that BlueField-3 uses QSFP112/56/28 cables and transceivers, not OSFP devices.

Optech supports customers in selecting the correct combination of QSFP112, OSFP, fiber type, reach, coding and protocol configuration for NVIDIA-based AI clusters. This helps reduce deployment risk and improves interoperability across high-speed InfiniBand and Ethernet environments.

Key Benefits of Optech 400G QSFP112 Transceivers

1. High Bandwidth for AI and HPC Workloads

With 400G per port, QSFP112 transceivers provide the bandwidth required for AI training, GPU clustering, machine learning, cloud computing and high-performance storage networks.

2. Compact QSFP-Based Upgrade Path

QSFP112 gives legacy QSFP users a practical path to 400G, helping data centers increase port speed while maintaining a compact and familiar module footprint.

3. Support for InfiniBand and Ethernet

Optech 400G QSFP112 modules are suitable for both InfiniBand and Ethernet architectures, giving customers flexibility when building AI, HPC and cloud networks.

4. NVIDIA-Oriented Compatibility

Optech QSFP112 transceivers are designed for NVIDIA-based deployments, including ConnectX-7 and BlueField-3 adapter/DPU environments where QSFP112 interfaces are used. Proper coding and configuration can be provided according to the target device and network protocol.

5. SR4 and DR4 Options for Different Cabling Needs

SR4 is ideal for short-distance multimode fiber links inside racks or nearby racks, while DR4 is suitable for single-mode links over longer distances inside data centers or campus environments.

6. Reliable 100G-PAM4 Optical Performance

400G QSFP112 uses four lanes of high-speed PAM4 signaling, requiring strict signal integrity, thermal performance and optical testing. Optech provides quality-controlled optical modules for stable high-speed deployment.

Application Scenarios

AI Training Clusters

Large AI clusters require high-bandwidth, low-latency interconnects between GPU servers and switches. Optech 400G QSFP112 SR4 and DR4 modules help support fast data exchange across GPU nodes, improving AI training efficiency.

NVIDIA ConnectX-7 and BlueField-3 Deployments

For servers using NVIDIA ConnectX-7 QSFP112 adapters or BlueField-3 QSFP112 DPUs, Optech 400G QSFP112 transceivers provide high-speed optical connectivity for InfiniBand and Ethernet fabrics.

Dual 400G InfiniBand / Ethernet Switch Architectures

In high-performance networks, adapter-side QSFP112 connections may be linked to NVIDIA switch-side OSFP or twin-port OSFP systems using the correct interconnect architecture. This is important for avoiding form-factor mismatch and ensuring stable 400G operation.

Cloud Data Centers

Cloud service providers can use 400G QSFP112 optical modules to scale spine-leaf networks, storage fabrics and east-west traffic inside large data centers.

HPC and Research Networks

High-performance computing environments require fast node-to-node communication. 400G QSFP112 DR4 is suitable for longer single-mode fiber links, while SR4 is ideal for short-reach multimode interconnects.

High-Speed Storage and Data Processing

AI storage, distributed databases and big data platforms require high-throughput network paths. Optech 400G QSFP112 modules help reduce network bottlenecks and improve data movement efficiency.

Why Choose Optech?

Optech is a Taiwan-based optical transceiver manufacturer with strong experience in data center, telecom, AI and high-speed networking applications. Optech provides optical transceivers, DAC/AOC cables and customized compatibility solutions for multiple network platforms.

For 400G QSFP112 applications, Optech can support:

• 400G QSFP112 SR4 and DR4 solutions
• InfiniBand and Ethernet application support
• NVIDIA-oriented compatibility testing
• Custom coding and labeling
• Multi-brand switch and adapter validation
• Technical support for AI data center deployments
• Stable quality control for high-speed optical modules

With strong engineering capability and flexible manufacturing support, Optech helps customers build reliable 400G AI network infrastructure with professional optical connectivity solutions.

FAQ

1. What is a 400G QSFP112 transceiver?

A 400G QSFP112 transceiver is a high-speed optical module using four 100G-PAM4 lanes to deliver 400G total bandwidth in a compact QSFP-style form factor.

2. What is the difference between QSFP112 SR4 and QSFP112 DR4?

QSFP112 SR4 is designed for short-reach multimode fiber links, typically up to 50 meters. QSFP112 DR4 uses single-mode fiber and is suitable for longer data center links, typically 100 meters or up to 500 meters depending on the exact specification and project requirement.

3. Can Optech 400G QSFP112 transceivers support InfiniBand?

Yes. Optech 400G QSFP112 transceivers can be used in InfiniBand applications when properly coded and matched with the target NVIDIA adapter, DPU or network environment.

4. Can Optech 400G QSFP112 transceivers support Ethernet?

Yes. Optech 400G QSFP112 modules are suitable for 400GbE data center networks and can be configured for Ethernet applications.

5. Are QSFP112 transceivers compatible with NVIDIA ConnectX-7?

QSFP112 transceivers are used with ConnectX-7 QSFP112 adapter versions. ConnectX-7 also has OSFP versions, so the correct form factor must be selected according to the actual adapter model.

6. Are QSFP112 transceivers compatible with NVIDIA BlueField-3?

Yes, BlueField-3 platforms include QSFP112 interface options. NVIDIA documentation states that BlueField-3 uses QSFP112/56/28 cables and transceivers, not OSFP devices.

7. Can QSFP112 be inserted into an OSFP switch port?

No. QSFP112 should not be inserted into an OSFP switch cage. NVIDIA documentation states that QSFP112 cannot be used in OSFP switches. For OSFP switch-side connections, the correct OSFP or twin-port OSFP interconnect must be selected.

8. Why is 400G QSFP112 important for AI networks?

AI networks need high bandwidth and low latency for GPU-to-GPU, server-to-switch and storage communication. 400G QSFP112 helps increase network throughput and supports the performance requirements of AI training and inference clusters.

9. Does Optech provide custom coding for NVIDIA environments?

Yes. Optech can provide coding, labeling and compatibility support according to customer requirements and target network equipment.

10. How can I choose between SR4 and DR4?

Choose SR4 for short multimode fiber links inside racks or nearby racks. Choose DR4 for single-mode fiber links where longer reach is required within the data center or campus network.

Conclusion

Optech 400G QSFP112 SR4 and DR4 transceivers provide a powerful upgrade path for AI data centers, HPC systems, cloud networks and NVIDIA-based InfiniBand/Ethernet environments. With support for high-speed 100G-PAM4 signaling, compact QSFP112 form factor, SR4 and DR4 options, and NVIDIA-oriented compatibility, Optech helps customers build reliable 400G interconnect infrastructure for next-generation AI networks.