Startup’s Metal Stacks Tackle AI’s Overheating Crisis
▼ Summary
– Nvidia’s upcoming Rubin Ultra GPUs (expected 2027) will consume up to 600 kilowatts per rack, nearly double the power of current fast EV chargers.
– Alloy Enterprises has developed a metal sheet bonding technology to create seamless copper cooling plates for high-power data center components.
– Their stack forging process produces solid, non-porous cold plates with 35% better thermal performance than competitors and no leaking seams.
– The technology enables cooling of peripheral chips (20% of server cooling load) that previously had no liquid cooling solutions available.
– Alloy works directly with data center customers to design custom cooling plates and has seen high demand since announcing their copper product.
The soaring power demands of next-generation AI hardware are pushing data center cooling systems to their absolute limits. Nvidia’s upcoming Rubin Ultra GPUs, slated for a 2027 release, are projected to consume a staggering 600 kilowatts per rack, a figure that nearly doubles the output of today’s fastest electric vehicle chargers. This unprecedented energy density creates a critical thermal management challenge, forcing engineers to find innovative ways to dissipate immense amounts of heat.
One startup, Alloy Enterprises, believes its unique metal fabrication process holds the key. The company has engineered a method to produce solid copper cooling plates specifically for GPUs and their peripheral components, such as memory and networking chips. These supporting parts are often overlooked but can contribute roughly 20% of a server’s total thermal load.
Ali Forsyth, co-founder and CEO of Alloy Enterprises, highlighted the shifting priorities. “When server racks operated at 120 kilowatts, that 20% wasn’t a primary concern,” she explained. “But with racks now hitting 480 kilowatts and heading for 600, engineers must find a way to liquid-cool every single component, including those for which no standard solutions currently exist.”
The startup’s approach utilizes a form of additive manufacturing, building objects layer by layer, to create cold plates that can fit into confined spaces and endure the high pressures inherent in liquid cooling systems. However, Alloy does not rely on conventional 3D printing. Instead, its proprietary technique involves taking individual sheets of metal and bonding them together using a combination of intense heat and pressure. This method, while more costly than traditional machining, proves more economical than 3D printing.
The final product is a cold plate that behaves as a single, monolithic block of metal. It lacks the seam found in machined products and, unlike porous 3D-printed versions, is completely solid. “We achieve the fundamental properties of the raw material,” Forsyth stated. “The resulting copper is just as robust as if it had been machined from a solid block.”
Conventional cold plates are typically machined, a process requiring large tools that can only work on one half of the plate at a time. The two halves are subsequently fused through sintering, which uses heat to meld metal powders. This fusion line introduces a potential weak spot that could leak under extreme pressure. Alloy’s alternative, a diffusion bonding technique it calls stack forging, produces seamless cold plates, eliminating this vulnerability.
An added advantage of stack forging is its ability to create extremely fine internal features, some as small as 50 microns, about half the width of a human hair. These minute channels permit a greater volume of coolant to circulate past the metal. According to Forsyth, this design yields cold plates with a 35% improvement in thermal performance compared to competing products.
Given the intricacies of stack forging, Alloy takes the lead on most internal design work. Clients provide essential specifications and dimensions, and the startup’s proprietary software translates these parameters into a form compatible with its manufacturing workflow.
Inside Alloy’s factory, the process begins with rolls of copper being prepared and cut to the required size. A laser then precisely cuts out the internal features. To prevent certain design elements from bonding, an inhibitor is applied to specific areas. Once prepared, each individual layer of the cold plate is carefully aligned and stacked before entering a diffusion bonding machine. This machine applies the necessary heat and pressure to permanently fuse the stack into a single, seamless piece of metal.
Forsyth noted that the company is collaborating with “all the big names” in the data center industry, though she declined to name specific partners.
Initially developed for a common aluminum alloy, the technology was adapted for copper after significant interest emerged from the data center sector. Copper’s superior thermal conductivity and corrosion resistance made it an ideal material. The response to the product’s announcement in June was immediate and overwhelming. “Things just blew up,” Forsyth remarked.
Image: An illustration of Alloy Enterprises’ stack forging process, showing layers of copper being fused together.
(Source: TechCrunch)
