This startup’s metal stacks could help solve the massive heat problem faced by artificial intelligence

When Nvidia announced this Robin series of GPUs in March also dropped a bomb: racks built with the Ultra version of the chip, which is expected to be released in 2027, can draw up to 600 kilowatts of electricity. That’s nearly twice the amount of power that some of today’s fastest electric vehicle chargers can provide.

As data center racks become power-hungry, one of the biggest hurdles will be figuring out how to keep them cool. One startup thinks stacks of metal are the answer.

Bullion companies It has developed a technology that turns copper sheets into solid cooling plates for graphics processing units, peripheral chips, and supporting components such as memory and networking devices that account for about 20% of a server’s cooling load.

“We didn’t care much about that 20% when the racks were 120 kilowatts,” Ali Forsyth, co-founder and CEO of Alloy Enterprises, told TechCrunch. But now, with rack capacity at 480 kilowatts on its way to 600 kilowatts, engineers have to figure out how to liquid cool everything from RAM to networking chips, parts for which there are no solutions available today.

Alloy’s approach uses additive manufacturing (building objects layer by layer) to produce cold panels capable of being squeezed into tight spaces while withstanding the high pressures that liquid cooling can require.

But the startup doesn’t use 3D printing. Rather, it takes sheets of metal and forces them together using a combination of heat and pressure. It is more expensive than traditional machines, but cheaper than 3D printing.

The result is a cold plate that is, for all intents and purposes, a single block of metal. There are no seams, unlike machined products, and it is solid metal, unlike 3D printed versions, which can be porous. “We hit the properties of the raw materials,” Forsyth said. “The brass is just as strong as if you had machined it.”

Most panels are cold milled, a process that uses tools to carve features. Due to the large size of the tooling, each half of the plate must be machined separately. The two halves are then sintered together – a process in which metal powders are combined using heat – creating a seam that is likely to leak under high pressure. An alloying process, a type of diffusion bonding called stack forging, creates cold, seamless panels.

Stack shaping can also create smaller features, down to 50 microns, about half the width of a human hair, allowing more coolant to flow through the metal. The alloy cold panels have 35% better thermal performance than competitors, Forsyth said.

Due to the complexities of stack forging, Alloy does most of the in-house design. Customers provide key specifications and dimensions, and the startup’s software helps translate those specifications and dimensions into a form that suits the company’s manufacturing process.

In the bullion plant, the copper coils are first prepared and cut to size. The features are then cut using a laser. Parts of the design that the company does not want to connect to each other are coated with a sealant. When finished, each slice of cold plate is scored and stacked before heading to the diffusion bonding machine, 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, though she did not reveal specific details.

Initially, the company designed the technology to work with widely used aluminum alloys, but as it received more interest from data centers, it transitioned the process to work with copper, which conducts heat well and resists corrosion. When Alloy announced the product in June, “things blew up,” Forsyth said.