Broadcom Tomahawk 6 Scaling AI Networks with the World’s First 102.4 Tbps Ethernet Switch

Tomahawk 6 is the world’s first 102.4 Tbps Ethernet switch, designed to meet the demands of massive AI infrastructure. In this session, we’ll show how it enables both scale-up and scale-out networking, with unmatched bandwidth, energy efficiency, and congestion control. We’ll also debunk common myths about AI networking and explain why Ethernet has become the fabric of choice for the world’s largest GPU clusters.

Pete DelVecchio introduced Broadcom’s Tomahawk 6, a 102.4 Tbps Ethernet switch designed for both scale-up and scale-out AI networking. Tomahawk 6 doubles the bandwidth and SERDES speed of its predecessor, Tomahawk 5, and incorporates features to enhance load balancing and congestion control. DelVecchio emphasized that Ethernet has become the dominant choice for AI scale-out networks and is gaining traction in scale-up environments due to its open ecosystem and the ability to partition large clusters for different customers.

Tomahawk 6 comes in two versions: one with 512 lanes of 200G SERDES and another with 1,024 lanes of 100G SERDES. The presenter highlighted that Tomahawk 6 is built on a multi-die implementation, with a central core for packet processing and chiplets for I/O. The chip is designed for both scale up and scale out applications. For scale-up applications, Tomahawk 6 can support 512 XPUs in a single-hop network.

The presentation also touched upon power efficiency, emphasizing that Tomahawk 6 enables two-tier network designs, which significantly reduce the number of optics required compared to three-tier networks, leading to lower power consumption and reduced latency. DelVecchio also discussed advanced features like cognitive routing with global load balancing, telemetry, and diagnostics for proactive link management. Broadcom emphasized that Tomahawk 6 is an open, interoperable solution that works with any endpoint and offers flexibility in telemetry, load balancing, and congestion control.