Thermal Grizzly's Experimental Direct-Die CPU Block Uses Diamond Sheets Priced at €500 Each

Thermal Grizzly has been pushing the boundaries of cooling technology with an experimental direct-die CPU block that could redefine how high-performance processors are cooled. During its Computex 2026 booth, the company showcased a prototype that uses industrial diamond sheets for thermal management. Sasha Robey, Senior Marketing Manager at Thermal Grizzly, shared that the block features two ultra-thin diamond sheets coated with a special metal to ensure proper adhesion of liquid metal.

This direct-die block sits directly on the CPU's silicon, removing any intermediary materials that might slow heat transfer. The model on display is tailored for AM5 processors with two CCDs, such as the Ryzen 9 9950X. However, users would need to delid their CPUs to access the silicon, a process that requires precision and care to avoid damaging the processor.

Inside the block, the layout is carefully designed to accommodate each chip. The I/O chip is cooled using lapped metal, while the two CCDs are cooled by razor-thin CVD diamond inserts. These diamonds are produced via Chemical Vapor Deposition (CVD), a method that creates lab-grown diamonds with thermal properties similar to natural ones.

The Thermal Conductivity of CVD Diamonds

The thermal conductivity of CVD diamonds is three to four times better than traditional cooling blocks used in the industry. Copper, a common material in cooling solutions, has a thermal conductivity of around 390 W/mK. In contrast, the CVD diamond in this block reaches up to 2200 W/mK. This significant improvement could change how high-end CPUs are cooled, especially in extreme scenarios.

Despite the impressive performance, Robey acknowledges that this project is still experimental and may never reach the market. Each diamond insert alone costs €500, and the total cost of the block could be €1500 or more. “I think this will never make it to the market, but yeah, an interesting example of what is possible,” Robey says.

New Coatings for Thermal Grizzly's Blocks

While the diamond block remains a concept, Thermal Grizzly is working on more practical innovations. The company has partnered with Swiss company Platit to develop new coatings for its non-diamond CPU and GPU blocks. These coatings include:

  • A carbon-based option (light gray)
  • A nitride-based option (dark gray)
  • A oxynitride-based coating (rainbow)

Robey explains that the goal is to move away from nickel-plating, which is prone to corrosion and requires a long wait time for processing. “Plus, for us, it means when we have to ship blocks out for nickel plating, we wait four weeks or more sometimes to get products back,” she says.

The TG O coating, which features a rainbow patina, has been particularly eye-catching. The effect is caused by the thinness of the coating, which allows light to reflect in a way that creates a rainbow-like appearance. “Everybody likes the rainbow one,” Robey notes, “and it looks like rainbow because it's so thin that the light reflects in a way that we see rainbow.”

Thermal Grizzly is still evaluating which coatings to offer and whether they will be available as customization options for its products.