Breakthrough Cooling Technology

A revolutionary microprocessor cooling technology for data centers, Low-Chill™, is available from HRL Laboratories immediately for demonstrations and commercialization opportunities. Developed under co-investment with the ARPA-E COOLERCHIPS program, our groundbreaking direct liquid cooling approach enables future high power GPUs and megawatt rack densities in modern data centers without the cost and complexity of two-phase cooling systems while supporting low-water usage cooling architectures. The Low-Chill™ architecture has undergone long-duration testing, demonstrating durable, stable thermal performance with minimal degradation over time.

An innovative approach

A novel cooling block architecture that uses a 3D-printed manifold to distribute coolant through hundreds of short flow paths directly over the processor. By delivering cold coolant uniformly across the die, the design avoids the long flow channels and friction losses that constrain conventional cooling blocks. With this approach, HRL reduced the state-of-the-art thermal interface resistance to 8.2°C/kW.

  • Extends single-phase liquid cooling well into the next decade
  • Data centers can avoid higher-cost, more complex two-phase cooling which requires vaporizing and re-condensing the cooling fluid

HRL's highly effective Low-Chill™ technology serves as a drop-in replacement for existing data center cooling systems. All parts are commercially available or can be produced at scale with current 3D printing technology.

The Low-Chill™ cooling block architecture can be produced in a range of materials, including polymers and metals, while delivering consistent thermal performance across material choices.

Low-Chill™ direct liquid cooling

  • Ultra-low < 8.2°C/kW thermal resistance
  • Ultra-low < 1% IT power for pumping
  • Ultra-low < 1 psi pressure drop

This Low-Chill™ approach extends single-phase cooling to MW racks using a 3D-printed manifold to enable low thermal resistance and low-pressure drop.

Technology

  • Optimizes readily for any chip size or power
  • MW racks ready now with single-phase direct liquid cooling
  • Cost equivalent to existing liquid cooling
  • Enables elevated temperature cooling architectures compatible with dry air cooling and reduced water consumption

Implementation

  • High-volume supply chain ready to support components
  • Validated 3D printing suppliers for the manifold; all other components are standard
  • Existing and forward-looking comprehensive IP protections

Designed for data centers

HRL's single-phase water-cooling solution can cool 3000W per die vs 2100W per die today at <1% IT power. This applies broadly to future generations of NVIDIA and AMD GPUs. The novel cooling block enables 40% higher power densities or 10X lower pumping power compared to current state-of-the-art. This enables more AI Tokens per Watt (TPW). Also, the solution is compatible with current commercial-off-the-shelf (COTS) direct liquid cooling components.

Conserving water

Data center water consumption is driven primarily by heat rejection rather than on-chip cooling. When paired with hot-water coolant loops and dry air coolers, HRL's Low-Chill™ approach can reduce water use by eliminating evaporative cooling. Results depend on the facility's heat rejection architecture.

Compare against current cooling blocks

Current cooling technology relies on long intra-channel flow paths along hot fins.

  • Large friction-induced pressure loss = limits efficiency
  • Long sections of "fully developed" flow = diminishes thermal performance
  • Difference in coolant temperature (center to periphery) = less cooling over the chip

HRL leverages hundreds of short flow loops, well beyond even the most advanced and intricate conventionally machined manifolds, resulting in low-pressure drop and uniform cold coolant.

Performance data

Comparison notes:
  • Increases feasible rack power density versus commercial technologies
  • Cools 1KW with <5W of pump power
Comparison notes:
  • Short flow paths result in much lower pressure drop
  • Lower pressure drop yields significantly reduced pumping power

HRL is seeking partners to incorporate this technology into next generation data center cooling. Please reach out to understand more about the technology and explore partnering opportunities.

For more information, contact us at lowchill (at) hrl.com.


Additional references


HRL Laboratories pioneers the next frontiers of physical and information science. Delivering transformative technologies in automotive, aerospace and defense, HRL advances the critical missions of its customers. Using its high-performance technology and experience from aerospace, HRL developed this high-performing cooling block for data centers.

As a private company owned jointly by Boeing and GM, HRL is a source of innovations that advance the state of the art in profound and far-reaching ways. Learn more