半导体行业观察·2025-07-18 00:57Core Viewpoint - InfiniBand has been a dominant structure for high-performance computing (HPC) and AI applications, but its market position is challenged by Broadcom's new low-latency Ethernet switch, Tomahawk Ultra, which aims to replace InfiniBand and NVSwitch in AI and HPC clusters [3][5][26]. Group 1: InfiniBand and Its Evolution - InfiniBand gained traction due to Remote Direct Memory Access (RDMA), allowing direct memory access between CPUs, GPUs, and other processing units, which is crucial for AI model training [3]. - Nvidia's acquisition of Mellanox Technologies for $6.9 billion was driven by the anticipated growth of generative AI, necessitating InfiniBand for GPU server connectivity [3][4]. - The rise of large language models and generative AI has propelled InfiniBand to new heights, with NVLink and NVSwitch providing significant advantages for AI server nodes [4]. Group 2: Broadcom's Tomahawk Ultra - Broadcom's Tomahawk Ultra aims to replace InfiniBand as the backend network for HPC and AI clusters, offering low-latency and lossless Ethernet capabilities [5][6]. - The development of Tomahawk Ultra predates the rise of generative AI, targeting applications sensitive to latency [5]. - Tomahawk Ultra's architecture allows for shared memory clusters, enhancing communication speed among processing units compared to traditional InfiniBand or Ethernet [5][6]. Group 3: Performance Metrics - InfiniBand's packet size typically ranges from 256 B to 2 KB, while Ethernet switches often handle larger packets, impacting performance in HPC workloads [7]. - InfiniBand has historically demonstrated lower latency compared to Ethernet, with significant improvements in latency metrics over the years, such as 130 nanoseconds for 200 Gb/s HDR InfiniBand [10][11]. - Broadcom's Tomahawk Ultra boasts a port-to-port jump latency of 250 nanoseconds and a throughput of 77 billion packets per second, outperforming traditional Ethernet switches [12][28]. Group 4: Competitive Landscape - InfiniBand's advantages in latency and packet throughput have made it a preferred choice for HPC workloads, but Ethernet technologies are rapidly evolving to close the gap [6][10]. - Nvidia's NVSwitch is also under threat from Broadcom's Tomahawk Ultra, which is part of a broader strategy to enhance Ethernet capabilities for AI and HPC applications [26][29]. - The introduction of optimized Ethernet headers and lossless features in Tomahawk Ultra aims to improve performance and compatibility with existing standards [15][16].