Broadcom Tomahawk 5: A network chip with a speed of more than 51.2 terabytes per second

Broadcom has completed its new StrataXGS Tomahawk 5 chipset for 51.2 Tbps Ethernet switches and has begun shipments to switch manufacturers. The officially named BCM78900 family can control up to 64 x 800GE, 128 x 400GE, or 256 x 200GE, as well as 256 x 100GE or 256 x 50GE ports. As a result, scalable switches, backbones, ciphers, or assembly can be built with a single chip. The BCM78900 family provides full L2 and L3 switching, routing and tunneling functions. It is software compatible with all StrataXGS products.

Tomahawk 5 chips belong to the category of high-root network adapters, i.e., switches on a chip with a high port density, and contain up to 64 integrated Peregrine SerDes (Serializer-Deserialize) cores with all eight 106 Gbit/s PAM4 SerDes (Pulse Amplitude Modulation) cores. Transceivers and associated PCS (Physical Coding Sub-layer) for which a variety of port types, media, and bands can be implemented. It is implemented as six on-chip ARM processors on a 5nm monolithic chip, which should also increase energy efficiency.

Also suitable for AI and ML groups thanks to its low latency

According to Broadcom, this is the first chip to feature 256 x 200GE ports. This makes it also suitable for flat AI/ML clusters with low latency. Due to its low response time and its common buffer architecture, it should also be suitable for RoCEv2 (RDMA over Converged Ethernet) and other RDMA (Direct Remote Memory Access) protocols.

It also offers advanced adaptive routing, hardware-based link failover, dynamic load balancing, high-resolution PTP (Precise Time Protocol) time synchronization and SyncE (Synchronous Ethernet). It also supports end-to-end congestion control features specifically designed to handle the large, low-entropy flows typical of AI/ML workloads. Broadcom has yet to announce which manufacturers will use the Tomahawk 5 chips for their switches. The latest update to the Tomahawk series was released in 2019.