When Nvidia introduced its Rubin GPU lineup in March, it made headlines by revealing that racks equipped with the Ultra chip—anticipated for a 2027 launch—could consume as much as 600 kilowatts of power. That’s almost double the output of today’s most powerful EV chargers.
As data center racks demand ever more energy, a major challenge will be managing their cooling. One startup believes the solution lies in stacks of metal.
Alloy Enterprises has created a method that transforms copper sheets into robust cooling plates for GPUs and other peripheral chips—components like memory and networking devices that make up about 20% of a server’s cooling requirements.
“That 20% wasn’t a big concern when racks were only 120 kilowatts,” said Ali Forsyth, Alloy Enterprises’ co-founder and CEO, in an interview with TechCrunch. But now, as racks reach 480 kilowatts and are on track for 600, engineers must find ways to liquid cool everything from RAM to networking chips—areas where current solutions don’t exist.
Alloy’s solution leverages additive manufacturing—building up objects layer by layer—to fabricate cold plates that fit into compact spaces and endure the high pressures required for liquid cooling.
Image Credits:Alloy Enterprises
However, the company doesn’t rely on 3D printing. Instead, it bonds metal sheets together using heat and pressure. This approach costs more than traditional machining but is less expensive than 3D printing.
The outcome is a cold plate that is essentially a single, solid piece of metal. Unlike machined products, there are no seams, and unlike 3D-printed versions, the metal is not porous. “We achieve the properties of raw material,” Forsyth explained. “The copper is as strong as if it had been machined.”
Most cold plates are produced by machining, which involves carving out features with large tools, requiring each half to be made separately. The halves are then joined through sintering—a process that fuses metal powders with heat—creating a seam that could leak under high pressure. Alloy’s method, a form of diffusion bonding called “stack forging,” produces seamless cold plates.
Stack forging also enables the creation of finer features, down to 50 microns—about half the width of a human hair—allowing more coolant to circulate. According to Forsyth, Alloy’s cold plates offer 35% better thermal efficiency than competing products.
Due to the intricacies of stack forging, Alloy handles most of the internal design work. Clients provide essential specifications and measurements, and the startup’s software converts these into a design compatible with their manufacturing process.
At Alloy’s facility, copper rolls are first prepared and cut to the required dimensions. A laser then carves out the necessary features. Areas that shouldn’t bond are coated with an inhibitor. Once ready, each layer of the cold plate is aligned and stacked before being placed in a diffusion bonding machine, where heat and pressure fuse the stack into a single metal unit.
Forsyth mentioned that the company is collaborating with “all the major players” in the data center industry, though she declined to name specific partners.
The technology was originally designed for a common aluminum alloy, but as interest from data centers grew, Alloy adapted the process for copper, which is highly conductive and resistant to corrosion. After Alloy unveiled the product in June, “interest skyrocketed,” Forsyth said.
