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

Thermal Grizzly has been experimenting with some truly cutting-edge cooling solutions that would appeal to any custom loop enthusiast. During a visit to its Computex 2026 booth, one product stood out: an experimental direct-die CPU block that uses industrial diamond sheets for thermal management. Sasha Robey, Senior Marketing Manager at Thermal Grizzly, explains that the block features two incredibly thin diamond sheets, which are coated with a special metal to allow liquid metal to adhere properly.

The direct-die block sits directly on the CPU silicon, eliminating any intermediary materials that might hinder heat transfer. The model on display is designed for AM5 processors, specifically those with two CCDs, making it ideal for a Ryzen 9 9950X. However, users would need to delid their processors to access the silicon, a process that can be risky if not done carefully.

Inside the block, you can see the layout where each chip will be placed. The I/O chip is cooled using lapped metal, while the two CCDs are cooled by razor-thin CVD diamond inserts. These diamonds are created through Chemical Vapor Deposition (CVD), a process that yields lab-grown diamonds with thermal properties comparable 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, commonly used in cooling solutions, has a thermal conductivity of around 390 W/mK. In comparison, the CVD diamond used in this block reaches up to 2200 W/mK. This significant improvement in thermal performance could revolutionize how high-end CPUs are cooled, especially in extreme scenarios.

Despite the impressive performance, Robey notes that this project is 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.