AI networking startups race to replace Nvidia's NVLink

As Nvidia expands its influence through its NVLink Fusion tech, rival networking vendors are scrambling to bring alternative interconnects and switches to market.

At the AI Infra Summit this week, Delos Data and Cornelis Networks officially entered the scale up networking race.

Scale-up fabrics, like NVLink, are what have allowed Nvidia to make eight, 72, and now 576 GPUs behave as one enormous AI accelerator.

To catch up, rivals like AMD have embraced emerging protocols like Ultra Accelerator Link.

Today, these protocols are largely being tunneled over standard Ethernet switches.

For instance, AMD is using Broadcom’s 102.4 Tbps Tomahawk 6-based switches connecting to custom I/O dies on the MI455X.

Purpose-built UALink switches and physical interconnects remain elusive, but that won’t be the case for long if Cornelis and Delos have their way.

The two companies are approaching this challenge from a few different angles, including standardization, software optimization, and physical hardware.

Setting the standard for the Never-Nvidia network At AI Infra on Monday, HPC-centric networking vendor Cornelis introduced the Active Compute Fabric (ACF), which seeks to establish an open architecture for scale up and scale out networking that integrates programmable compute into the fabric.

The standard signals Cornelis’ entry into the scale up networking arena.

Spun out of Intel in 2020, Cornelis’ Omni-Path tech was originally designed as a scale-out interconnect for high-performance computing applications, including supercomputers like Trinity and Lynx.

With the imminent launch of the company’s 800 Gbps-capable CN6000-series switches and NICs, the company has its sights set not only on bringing its tech to a broader audience through the open Ultra Ethernet protocol, but also on scale-up networking.

ACF expands on the mission of technologies like UALink and the Ethernet for Scale-Up Networking, another scale up networking protocol, to set a baseline for in-network compute capabilities across a wide range of hardware, not just Cornelis’ own CN-series parts.

One of the key technologies behind Nvidia’s NVSwitch ASICs is support for SHARP, which allows for things like in-network collectives to be offloaded to the switch ASICs, freeing up GPU compute and cutting down on communication overheads.