This startup’s metal stack could help solve AI’s huge heat problem

When Nvidia announced its Rubin series of GPUs in March, it also dropped the bombshell that racks with the Ultra version of the chips, scheduled to be released in 2027, could draw up to 600 kilowatts of power. That’s nearly twice as fast as today’s fastest EV chargers.

As data center racks become more power-hungry, one of the biggest hurdles becomes finding ways to keep them cool. One startup thinks chunks of metal are the answer.

Alloy Enterprises has developed a technology that turns sheets of copper into solid cooling plates for GPUs and peripheral chips, supporting components such as memory and networking hardware that make up about 20% of a server’s cooling load.

“When racks were 120 kilowatts, we didn’t really care about that 20%,” Ali Forsyth, co-founder and CEO of Alloy Enterprises, told TechCrunch. But now, as rack power reaches 480 kilowatts and is on the verge of reaching 600 kilowatts, engineers are having to find ways to water-cool everything from RAM to network chips, components for which there are currently no solutions available.

Alloy’s approach uses additive manufacturing (building objects layer by layer) to produce cold plates that can be squeezed into tight spots while withstanding the high pressures that liquid cooling demands.

But the startup doesn’t use 3D printing. Rather, it uses metal sheets and uses a combination of heat and pressure to force the bond. It is more expensive than traditional machining, but less expensive than 3D printing.

The result is a cold plate that is apparently a single block of metal. Unlike machined products, there are no seams, and unlike 3D printed versions, which can be porous, they are solid metal. “We looked at the properties of the raw materials,” Forsyth said. “Copper is just as strong as machined.”

Most cold plates are machined, a process that uses tools to cut out the shape. Due to the large size of the tool, each half of the plate must be machined separately. The two halves are then sintered together (a process that uses heat to fuse metal powders together). This creates seams that can leak under high pressure. Alloy’s process is a type of diffusion bonding called “layer forging” that produces seamless cold plates.

Laminate forging can also create smaller shapes up to 50 microns, about half the width of a human hair, allowing more coolant to pass through the metal. Forsyth says alloy cold plates have 35% better thermal performance than competitors.

Due to the complexity of layer forging, Alloy does most of the internal design. Customers submit key specifications and dimensions, and the startup’s software helps convert them into shapes suitable for the company’s manufacturing process.

At the alloy factory, rolls of copper are first prepared and cut to size. The feature is then cut out using a laser. The parts of the design that the company doesn’t want bonded to each other are coated with an inhibitor. Once completed, each slice on the cold plate is aligned and stacked before being sent to a diffusion bonder, which uses heat and pressure to press the stacked slices into a single piece of metal.

Forsyth said her company works with “all the big names” in the data center world, but declined to provide details.

The company originally designed the technology to work with the widely used aluminum alloy, but as interest from data centers grew, the company ported the process to work with copper, which is highly thermally conductive and resistant to corrosion. When Alloy introduced the product in June, “things just exploded,” Forsyth said.