FS N9550-32D 400G Switch Enables AI and HPC Clusters with 400G RoCE Networking

NicholasSep 12 20251 min read

As AI training scales up, a single model often requires thousands of GPUs working in parallel, making the network a critical determinant of overall performance. Hundreds of terabytes of data must be exchanged across clusters, demanding ultra-high throughput, while rapid parameter synchronisation makes latency a decisive factor for training efficiency. To meet these stringent requirements for bandwidth, latency, and lossless transmission, FS introduces the N9550-32D 400G switch, delivering 400G high-speed interconnects and AI-optimised features to provide a solid foundation for AI and HPC data centers.

AI/HPC Data Center Challenges in the Market Context

Exponential Traffic Growth

In AI training, data transmission volumes can reach TB or PB levels, far exceeding the capacity of traditional networks. Frequent data interaction between storage and computing units leads to a surge in network traffic. This surge in traffic poses a major challenge to traditional network architectures. Gartner predicts that by 2027, approximately 70% of new AI data centers worldwide will upgrade to 200G/400G networks to meet bandwidth requirements.

Latency Bottlenecks in GPU Synchronisation

In AI training, 30% of the time is spent on network latency, with only 70% used for computation. GPU clusters require nanosecond-level synchronization, and even microsecond-level latency can cause a sharp drop in computing power utilization. For example, a 10–20 microsecond delay between nodes can extend the training cycle by several days or even weeks, directly affecting the time-to-market of AI products. For enterprise-level AI applications, every week of early market launch can bring millions of dollars in competitive advantage.

Packet Loss and Congestion Risks

Unlike traditional web workloads, AI training requires near lossless data transmission. A 0.1% packet loss in Ethernet can reduce AI training throughput by 40% or more, forcing retransmissions and inflating compute costs. This has directly driven rapid growth in market demand for low-latency, lossless transmission technologies such as RDMA over Converged Ethernet (RoCE) and InfiniBand.

Scalability Constraints

Scaling from pilot projects to production AI clusters often means growing from hundreds to tens of thousands of GPUs. Traditional network architectures face challenges in port density, power consumption, and cost-efficiency, limiting scalability. Hyperscale AI/HPC clusters are becoming mainstream in the market, and the global hyperscale AI network equipment market is expected to exceed US$20 billion by 2026.

AI/HPC workloads are redefining data center requirements. Enterprises and cloud providers need ultra-high bandwidth (200G/400G), near-zero latency fabrics, lossless networking, and scalable architectures. Vendors that address these pain points not only meet technical challenges but also help customers accelerate AI innovation, reduce TCO, and gain market competitiveness.

N9550-32D: 400G Switch for AI and HPC Clusters

Training large models requires thousands to tens of thousands of GPUs to participate in collaborative computing, and network switches must ensure extremely low latency and high concurrent throughput to avoid wasting computing power. Against this backdrop, the FS N9550-32D 400G switch, with its architecture optimized for AI/HPC, is the ideal choice for connecting large-scale clusters.

Flexible High-speed Port Configuration

Equipped with 32 × 400G QSFP-DD ports, each 400G QSFP-DD port can be split into 4 × 100G or 2 × 200G ports via a splitter cable, enabling a single device to flexibly scale up to 128 × 100G connections. Ideal for building highly scalable top-of-rack and backbone switches to support demanding AI workloads.

This “hardware decoupling” capability perfectly aligns with the heterogeneous requirements of AI computing pools—supporting high-bandwidth direct connections for GPU nodes while providing cost-effective access solutions for storage nodes, enabling on-demand resource allocation.

Ultra-high Throughput Performance

With a switching capacity of 12.8 Tbps and a forwarding rate of 5210 Mpps, it can carry east-west traffic for large-scale AI clusters.

It supports MLAG multi-machine frame virtualization technology, which can build a flattened network of more than 100,000 GPUs. Through EVPN-VXLAN, it can logically pool AI computing power across racks, completely breaking through the scale limitations of traditional three-layer architectures for distributed training.

Dynamic Load Balancing (DLB) Technology

Equipped with built-in RoCEv2 capabilities, the 400G switch offers advanced features such as PFC, ECN, and dynamic load balancing, enabling low-latency, lossless communication for RDMA-based AI workloads—without requiring additional investment in network infrastructure.

High Reliability Design

By integrating the intelligent traffic scheduling capabilities of the Broadcom Tomahawk 3 chip, the 400G switch can detect burst traffic in AI training tasks in real time and dynamically adjust data path allocation.

For AI data centers that require continuous training 24/7, its modular design is equipped with 1+1 redundant hot-swappable power supplies and a 5+1 intelligent fan system, supporting zero-perception switching in the event of a single component failure.

Automated RoCE Deployment

RoCE EasyDeploy simplifies lossless network deployment by automating PFC and ECN configuration, reducing manual effort and minimising errors to accelerate high-performance fabric rollout for AI and HPC workloads.

Unified Management Platform

Pre-installed with the PicOS® operating system, supporting high levels of programmability and automation: including MLAG, ZTP, NetConf/RESTCONF, sFlow, AmpCon-DC management platform, etc.

The AmpCon-DC management platform manages PicOS® data center switches to configure, monitor, perform preventive troubleshooting, and maintain high-performance networks, thereby improving resource utilization and reducing operational costs. Enterprises can achieve fully automated operations and maintenance from Day 0 to Day 2+, improving management efficiency, saving labor costs, and shortening deployment cycles.

Want to learn more about the N9550-32D? Click here to download the N9550 Series Switch Product Information PDF.

FS 400G RoCE Lossless Network Solution

While the performance of a single device can alleviate some of the pressure on data centers, a true end-to-end solution is required to meet the network demands of AI and HPC scenarios.

The FS 400G RoCE solution was designed precisely for this purpose. This solution leverages NVIDIA® H100 GPUs and utilizes the N9550-32D 400G switch to build a 400G lossless RoCEv2 architecture for AI workloads, delivering higher bandwidth, lower latency, and high throughput to create a high-performance network.

Solution Advantages

High Bandwidth

The FS 400G RoCE solution is based on a 400G switch backbone interconnect, achieving a switching capacity of up to 25.6 Tbps per machine. For data training scenarios that often involve terabytes or even petabytes of data, this bandwidth ensures high-speed communication between GPU nodes, thereby accelerating model iteration and shortening the training cycle.

Low Latency

The solution leverages RoCE v2 technology and lossless Ethernet mechanisms to achieve microsecond-level end-to-end latency. Compared to traditional Ethernet, RoCE avoids performance degradation caused by packet loss and retransmission, enabling GPU clusters to maintain efficient synchronization and ensuring full utilization of computing power.

Scalable Architecture

The solution adopts a Spine-Leaf architecture design, offering high scalability. From small-scale AI experimental clusters to large-scale deployments with tens of thousands of GPUs, modular expansion can be easily achieved. As AI computing power demands continue to rise, this architecture ensures flexible network expansion without compromising overall performance.

Unified Management

Based on the PicOS® network operating system and AmpCon centralized management platform, the solution enables automated configuration, intelligent operations and maintenance, and real-time monitoring. Users can maintain complex network environments with lower labor costs, improving operational efficiency and stability.

Core values of N9550-32D

As a core switch in the Spine layer, the N9550-32D plays three key roles in the solution:

1. High-performance interconnection hub

Equipped with the Broadcom BCM56980 chip, the 400G switch provides 25.6 Tbps of bi-directional bandwidth and 32 400G QSFP-DD ports in a compact 1U design for high-density connectivity, serving as the core interconnection node between GPU servers and Leaf switches.

2. AI Communication Optimization

Native support for RoCE/RDMA lossless transmission protocols, with hardware acceleration enabling 400Gb/s line-rate forwarding. Unique cache management technology smoothly absorbs burst traffic, while PFC/ECN flow control mechanisms ensure priority for critical data streams.

3. Full Ecosystem Collaboration Engine

Deeply integrated with FS 400G optical modules and DAC/AOC cables to form an end-to-end optimized link. Combined with PicOS®'s open API interface, it enables seamless integration with management platforms, providing comprehensive performance optimization from the physical layer to the control layer.

The rapid advancement of generative artificial intelligence (AI) has captivated global audiences, driving AI and machine learning (ML) to the forefront of enterprise innovation. At the core of AI's transformative power are data centers, FS 400G RoCE lossless network solution offers a full-stack, integrated approach, spanning from network hardware to management software. Powered by 400G PicOS® Ethernet switches and AmpCon Management Platform, it delivers the highest performance for AI, machine learning, and HPC applications.

Conclusion

With its high-performance port configuration, AI-optimized protocols, and outstanding stability, the N9550-32D 400G siwtch stands as the cornerstone of FS 400G RoCE solution. FS remains committed to empowering enterprises with cutting-edge, reliable, and fully customized networking solutions.

Discover more about FS’s 400G AI solutions and get tailored design and deployment support to accelerate your AI clusters and drive innovation.