Broadcom extends its network chips to 800 Gbps

Introduction

Broadcom Inc. is looking to maintain its leading position in the Ethernet chip market with Tomahawk 5, a chip supporting port speeds of up to 800 Gbps and an aggregate throughput of 51.2 terabits per second, or Tbps. The vendor's standing in this niche faces its strongest competition in a long time, however, now that NVIDIA Corp. and Marvell Technology Inc. are also in the mix.

Broadcom's proficiency at developing high-speed communication chips has continued unabated, even as the company has amassed software and security properties. That is important because the company's franchise in Ethernet switching chips — a niche market but one that has proven crucial to hyperscale datacenters — is facing its most serious competition in years. Customers have hungered for other suppliers to hedge against Broadcom, and they now have the comfort of established names to turn to (e.g., Nvidia and Marvell). Broadcom's leadership position will not disappear overnight, but it will be important for the company to maintain the substantial investment it takes to produce these chips — even as its center of gravity shifts drastically with its pending $61 billion acquisition of VMware Inc.

Details

Secure data exchange, broadly speaking, allows an untrusted or less-trusted party to perform processing or other actions on a dataset in a highly controlled way in a manner designated by the originating party. This often works by applying data security mechanisms so that groups of data consumers with differing rights and permissions can work from and leverage the same datasets, with access and visibility that is strictly appropriate for them.

At the heart of modern datacenter and cloud networking are Ethernet switching chips. They sit inside switches and routers and send traffic to the proper destination ports. Broadcom's heritage in high-speed electronics has served it well here, as its Ethernet chips have long been leaders in the market, and the company frequently produces the first merchant chip of each new generation. Note the distinction of merchant chips. Large original equipment manufacturers such as Cisco Systems Inc. and Juniper Networks Inc. have long thrived on in-house switching application-specific integrated circuits and continue to develop them, although they have recently softened to the idea of buying off the shelf. This has happened again with the announcement in August of Tomahawk 5, which has throughput of 51.2 Tbps.

The chip features twice the bandwidth of Tomahawk 4, which was announced in late 2019. Broadcom has begun low-volume sampling of Tomahawk 5, but, as usual, certain customers had the design in hand earlier and have already been developing network switches built on it. Tomahawk is the Broadcom chip line developed for raw throughput, as opposed to Trident, which is laden with features targeting enterprise networks. While the chip supports 800 Gbps ports, it is also valuable in handling a higher density of lower-speed ports — 256 ports of 200 Gbps, compared with half as many ports for Tomahawk 4, for example. That makes it valuable in hyperscale settings, which involve massive volumes of east-west traffic — i.e., the traffic that gets pushed from one datacenter rack to another.

Tomahawk 5 is based on 5-nanometer process technology and is a monolithic design. In contrast, most major semiconductor vendors emphasize a chiplet approach, which involves building multiple small chips that are assembled into a whole to avoid the high costs and relatively low yields of highly complex chips. Broadcom has a long history of producing successful monolithic chip designs, which it says are more efficient, albeit more difficult to manufacture. The company does have chiplet-based products in production, meaning it will be ready should Tomahawk eventually need to make that transition.

In terms of power, Tomahawk 5 can consume 500 W in a typical setting, compared with the 350-400 W consumed by Tomahawk 4. While that is still within the limits of air cooling, it is feasible that future generations of Tomahawk and similar chips might start requiring (or at least encouraging) liquid cooling.

The vendor's Ethernet business faces its strongest competition in more than a decade. Formidable rivals have emerged in the past decade — no small feat given the complexity and expense of these chips — and have now been acquired by major semiconductor players. Specifically, Nvidia (which purchased Mellanox Technologies, Ltd. in 2019) and Marvell (which bought Innovium Inc. last year) can present serious challenges to Broadcom, especially in an environment dominated by the hyperscalers, which do not have a reputation for brand loyalty among suppliers.