Broadcom Ships First 25.6Tbps Switch on 7nm

Broadcom has started shipping its Tomahawk 4 switch to major cloud providers such as Alibaba and Microsoft. The chip packs 31 billion transistors on TSMC’s 7nm process and has 64 ports of 400GbE switching.

Two years after sampling its 12.8Tbps Tomahawk 3 silicon on TSMC’s 16FF+, segment leader Broadcom has now started shipping Tomahawk 4, the industry’s first switch capable of 25.6Tbps. Early adopters include Alibaba Cloud, Google Cloud, Microsoft, Tencent and Uber.

The 25.6Tbps throughput is achieved by packing 512 instances of 50G PAM4 SerDes. The monolithic 31 billion transistor chip is built on TSMC’s 7nm process. Broadcom says it remains committed to doubling the throughput of its switching silicon every two years.

As such, Tomahawk 4 has support for up to 64 ports of 400GbE switching or 256 ports of 100GbE, the highest radix of 100GbE solutions. According to Broadcom, it has a 75% lower power and cost than competitors. It also has some new features such as advanced load balancing mechanisms. Broadcom is also opening up its switch API as open source software with the introduction of Broadcom Open Network Switch APIs (OpenNSA).

Intel this year entered the switching market with the acquisition of startup Barefoot Networks, whose 7nm Tofino2 with chiplet architecture is capable of 12.8Tbps, while it stopped development of its Omni-Path fabric, launched its first 100Gbps Ethernet controllers and is moving to 400Gbps silicon photonics.

The Next Platform has a deep dive on Tomahawk 4.