Choosing 400G NICs by Network Interface: OSFP, QSFP-DD, and QSFP112 Explained
Nov 05, 20251 min read
In today’s AI, HPC, and cloud-driven world, the demand for higher bandwidth and lower latency is soaring. Massive data processing and real-time workloads are pushing networks to evolve faster than ever. As 400G networking becomes the backbone of next-generation infrastructure, network interface cards (NICs) are key to unlocking performance and scalability.
However, with multiple form factors—QSFP-DD, QSFP112, and OSFP—each tailored to specific deployment and upgrade needs, choosing the right 400G NIC is no simple task. This guide will walk you through the essentials of 400G NIC packaging, core technologies, and selection strategies, helping you build a network that’s not only fast today but ready for tomorrow’s demands.
400G NIC Network Interfaces: QSFP‑DD, OSFP, and QSFP112
In the 400 Gb/s networking era, the network interface type of a NIC determines its performance density, scalability, and power profile. The mainstream interfaces of 400G NICs includes QSFP-DD, OSFP, and QSFP112—each tailored to different 400G deployment needs.
QSFP-DD (Quad Small Form-Factor Pluggable Double Density)
Features eight electrical lanes, each operating at 50 Gbps PAM4, for a total of 400 Gbps.
Compact design enables high port density on switches and servers.
To achieve full 400G performance, QSFP-DD NICs are typically paired with QSFP-DD 400G optical transceivers or DAC/AOC cables.
Best suited for: high-density data centers requiring efficient 400G connectivity and smooth migration from previous QSFP-based infrastructure.
OSFP (Octal Small Form-Factor Pluggable)
Provides eight lanes at 50 Gbps or 100 Gbps per lane, supporting 400 Gbps and 800 Gbps data rates.
Designed with enhanced thermal management and higher power envelope, suitable for large-scale AI and HPC clusters.
Typically used with OSFP 400G/800G optical modules or cables for optimal performance.
Best suited for: performance-driven networks and AI infrastructures requiring high power and superior thermal control.
QSFP112
Uses four lanes at 112 Gbps per lane, enabling 400 Gbps total bandwidth in a compact QSFP form factor.
Offers improved signal integrity and power efficiency over previous QSFP56-based 200G designs.
Commonly deployed with QSFP112 400G optical transceivers or DAC/AOC cables to deliver full-rate 400G links.
Best suited for: enterprises upgrading from 200G to 400G networks with a focus on lower power and space efficiency.
How Should I Choose Between FS 400G NICs?
As data centers, AI clusters, and HPC environments move toward 400G networking, selecting the right adapter is critical for performance, compatibility, and scalability. FS offers a range of 400G network adapters from NVIDIA and Broadcom, designed to deliver high bandwidth, low latency, and robust security.
Brand | Model | Maximum Speed | Protocols | Ports | Network Interface | PCIe Version |
NVIDIA |  | 400GbE/NDR | InfiniBand & Ethernet | 1 | OSFP | PCIe 5.0 x 16 |
 | 400GbE/NDR | InfiniBand | 1 | OSFP | PCIe 5.0 x 16 | |
Broadcom |  | 400GbE | Ethernet | 1 | QSFP112-DD | PCIe 5.0 x 16 |
 | Single-port 400GbE Dual-port 200GbE | Ethernet | 2 | QSFP112 | PCIe 5.0 x 16 |
FS NVIDIA ConnectX-7 400G NIC
Supports 1 port with 400 Gb/s per port via OSFP interfaces.
Offers hardware acceleration features, including In-Network Computing, GPUDirect Storage, and advanced RoCE.
Provides inline hardware encryption (TLS, IPsec, MACsec) to offload CPU processing.
Ideal for AI/HPC, GPU clusters, and hyperscale cloud data centers, emphasizing low latency, high bandwidth, and high-density deployments.
FS Broadcom BCM957608 400G NIC
Single-port 400 Gb/s via QSFP-DD or QSFP112 interface.
Built-in TruFlow and TruManage engines enable virtual switch offload, low-latency inter-GPU communication, and tunnel processing.
Provides platform-level security (Silicon Root-of-Trust), suitable for high-density data centers and storage server environments.
Targets GPU clusters, AI/ML, HPC, cloud and enterprise data centers, as well as NVMe storage disaggregation applications.
NVIDIA ConnectX‑7 supports both InfiniBand and Ethernet for low-latency AI/HPC and cloud deployments, while Broadcom BCM957608 focuses on Ethernet with advanced virtual switch offload and platform security. Choose OSFP for high-density AI/HPC or QSFP‑DD/QSFP112 for 400G Ethernet upgrades to match your workload and throughput needs.
Conclusion
Choosing the right 400G NIC is essential to building a network that delivers high bandwidth, low latency, and future-ready scalability. By understanding the differences in network interfaces—OSFP, QSFP-DD, and QSFP112—and evaluating the specific features of NVIDIA and Broadcom adapters, you can match performance, compatibility, and deployment requirements to your workload.
FS provides a full range of validated 400G NICs, optics, and cables to ensure plug-and-play deployment, robust security, and seamless upgrades. Whether you’re expanding AI/HPC clusters, modernizing enterprise data centers, or preparing for next-generation cloud infrastructure, the right 400G NIC will empower your network to meet today’s demands and tomorrow’s growth.