Why Liquid Cold Plate Design Is Critical to AI’s Thermal Future

The pursuit of performance has always driven cooling innovation, from the water-cooled mainframes in the 1960s, the overclocking culture that turned thermal management into an art form, to the precision cold plates enabling today’s AI supercomputers.

As chip power climbs beyond 500 W per device and rack densities exceed 80 kW, air cooling can no longer keep up. Direct-to-chip (DTC) liquid cooling with cold plates has become the new standard for AI accelerators, CPUs, and high-density compute modules.

At this scale, the most consequential engineering happens at the cold plate itself. This article explores practical choices for engineering cold plates in the AI era — with attention to performance trade-offs, production scalability and future adaptability.

The power required to train frontier AI models is doubling annually. Source: https://epoch.ai/data-insights/power-usage-trend

Why Cold Plates Matter Now: The Key Interface for Heat Removal

Cold plates are the interface where thermal reality meets compute ambition. Acting as precision heat exchangers, they extract heat from chips into a circulating coolant, maintaining stable junction temperatures during heavy or transient loads.

Uniform heat removal is critical: uneven flow leads to hot spots, throttling and long-term material fatigue. Geometry and flow distribution determine whether a device sustains peak performance or derates under pressure.

Effective cold plate design gives architects design headroom, enabling higher power envelopes, greater density and longer hardware life with lower total cost of ownership.

Up to 85°C, GPU performance typically remains at maximum unless continuously stressed.​ Between 90–95°C, thermal throttling begins, resulting in clock speed reductions and gradual performance loss (≈5–20%).​ Above 95°C, drop-off becomes much more pronounced; severe cases (near 100°C) can reduce performance by up to 50% and sharply increase risk of hardware failure.​ Source: Based on industry data (ServerMania’s 2025 GPU temperature guide), showing GPU performance degradation as junction temperature increases, structured according to observed failure/throttle thresholds widely cited across a variety of high-performance computing operations.

The Fundamentals of Designing a Cold Plate

Optimizing cold plate performance is a balance between geometry, flow management and manufacturability. Every design choice affects how heat moves through the plate, how evenly coolant is distributed and how reliably the system performs under load.

Internal Geometry of Cold Plates: Channels, Manifolds and Surfaces

Internal geometry governs how fluid spreads across the chip and how effectively heat is removed.

• Channels: Straight parallel channels are easy to machine and provide predictable pressure drops, but risk maldistribution without well-designed manifolds.
• Advanced topologies: Manifolded parallel flow, crossflow paths or localized pin-fin regions enhance uniformity and target high-flux areas.
• Surface features: Microfins or turbulators break boundary layers and increase convection, but heighten sensitivity to particulates.
• Manifolds: Balanced inlet and outlet design prevents stagnant zones and uneven flow, maintaining consistent thermal performance.

Managing Hotspots and Transients in Cold Plates

AI accelerators, GPUs and CPUs rarely operate at steady state; workloads fluctuate in milliseconds. Cold plates must absorb these transient heat loads without depending solely on system-level control.

• Distributed flow paths, appropriate internal volume and well-structured channels help smooth temperature excursions and maintain stability during burst workloads.
• Maintaining junction temperatures below around 85 °C is widely recognized by industry best practice for reliability and aligns with JEDEC methodologies for qualifying long-term device health. However, manufacturers may specify higher maximum operating junction temperatures in accordance with JEDEC standards, and durability must be validated at these published limits.

This dynamic response is key to protecting both short-term thermal stability and long-term component health by operating within manufacturer and industry guidelines.

Balancing Heat Transfer and Pressure Drop in Cold Plates

Greater heat transfer often comes at the cost of higher pressure drop. Adding surface area or complex flow paths enhances cooling but increases demand on pumps and seals.

The objective is to find the right equilibrium between thermal resistance, mechanical strength and hydraulic performance.

• Aggressive geometries can cause erosion in high-velocity zones or thin fins.
• Pressure management prevents seal stress and leakage over time. Higher pressures can start to see mechanical stress deformation issues – the dreaded ‘potato chipping’ of a plate.
• A balanced design maintains strong thermal performance while keeping materials within safe mechanical limits.

Together, these geometric and hydraulic fundamentals form the foundation on which material selection and long-term reliability are built.

Cold plate performance enhancement based on parametric modeling of multiple structures. Figure 7 compares temperature, pressure drop, outlet temperature and temperature uniformity across three cold plate designs. The results show that geometry has a major impact on performance. Source: https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2022.1087682/full

Single-Phase vs Two-Phase Cold Plate Solutions

Cold plates typically operate in one of two thermal regimes: single-phase or two-phase cooling. Each with distinct design, control and integration considerations.

Single-phase cooling (also known as 1P) uses a liquid that remains in one state, such as water, water-glycol, or a dielectric fluid. Heat is removed through sensible heating as the fluid warms. These systems are mechanically simple, easy to manage, and integrate well with standard pumps and filtration.

Two-phase cooling (also referred to as Pumped 2-Phase or P2P) introduces controlled boiling within the cold plate. As the fluid vaporizes, it absorbs heat through the latent heat of vaporization, transferring more energy per unit mass. This enables tighter temperature control but requires precise management of pressure, vapor quality, and flow stability.

In practice, the choice between single or two-phase is not a contest but a trade-off. Single-phase systems deliver robustness and straightforward integration, while two-phase designs offer higher heat flux capacity and superior temperature uniformity when system complexity can be justified. For most near-term deployments, single-phase remains the mainstream solution, with two-phase solutions gaining traction as power demands continue to rise.

The Role of Additive Manufacturing in Cold Plate Design

Additive manufacturing (AM) is reshaping how cold plates are designed and produced, especially where complex internal features or integrated manifolds are required. Building a plate as a monolithic component removes welds, gaskets and brazed joints, eliminating many leak paths and tolerance stack-ups.

AM also enables:

• Conformal geometries that match irregular layouts.
• Integrated ports and mounting features reducing part count.
• Precise control over flow paths for uniform performance and balanced pressure.
• Superior mechanical strength and flatness of contact surfaces.

Conventional machining and brazed assemblies remain effective for simpler layouts or when cost and throughput are the primary drivers. The best outcomes align manufacturing methods with geometry complexity, tolerance and production scale, ensuring both technical performance and commercial viability.

3D printed cold plate cut in half. Internal fins can be varied to control coolant flow paths to eliminate hot spots. Source: Conflux Technology

AI Future-Readiness is about Designing Cold Plates for Iteration

Modern cold plate programs are being built for iteration. Cooling architectures that can adapt as quickly as the hardware advances;

• Modular designs with standardized interfaces let plates evolve alongside changing chip layouts and power envelopes
• Additive manufacturing accelerates that adaptability, allowing geometry refinements and manifold updates to be implemented rapidly and at low tooling cost.

This shift reflects a broader mindset change from static optimization to a focus on continuous evolution—where cooling hardware develops in parallel with silicon.

In the end, cold plates remain the quiet core of the liquid-cooling revolution. Their geometry, materials and precision define how efficiently the world’s most powerful machines operate. Future-ready designs will not just manage heat, they will enable the next era of scalable, serviceable and upgradeable computing.