The Rise of Liquid Immersion Cooling in Data Centers

LiquidStack and Submer have pioneered a novel approach to data center cooling – submerging servers in specialized liquids to enhance energy efficiency and reduce environmental impact. Now, Microsoft is joining this movement, entering the liquid-immersion cooling market with its own innovative solution.

Microsoft's Innovative Cooling System

Microsoft has developed a unique liquid, engineered to boil at 122 degrees Fahrenheit, which serves as a highly effective heat sink. This allows servers to operate at peak performance without the risk of overheating.

The vapor generated during the boiling process is then efficiently reconverted into a liquid state through contact with a cooled condenser located within the server tank’s lid.

According to Husam Alissa, a principal hardware engineer at Microsoft’s datacenter advanced development team, “We are the first cloud provider that is running two-phase immersion cooling in a production environment.”

A Well-Established Cooling Technique

While Microsoft’s announcement is significant, liquid cooling itself isn’t a new concept. It’s a widely used method for thermal management, commonly found in automotive engines to maintain optimal operating temperatures.

Addressing the Challenges of Moore’s Law

As processor speeds and performance continue to increase, driven by the ongoing pursuit of Moore’s Law, the demand for more robust cooling solutions becomes critical. Modern central processing units (CPUs) now consume over 300 watts per chip, a substantial increase from the 150 watts of previous generations.

Similarly, graphics processing units (GPUs), essential for tasks like Bitcoin mining, artificial intelligence, and high-end graphics rendering, each consume more than 700 watts.

Building on Existing Technologies

It’s important to acknowledge that Microsoft isn’t the first to implement liquid cooling in data centers. Bitcoin mining operations have utilized this technology for years.

In fact, LiquidStack originated from a bitcoin mining operation, demonstrating the technology’s proven effectiveness and leading to its commercialization.

The Limitations of Air Cooling

“Air cooling is not enough,” emphasizes Christian Belady, vice president of Microsoft’s datacenter advanced development group. The increasing heat generated by processors necessitates more direct and efficient cooling methods, such as immersion cooling, which allows for direct heat removal from the chip surfaces.

For Belady, this technology effectively translates the density and advancements of Moore’s Law to the datacenter infrastructure.

Energy Efficiency Gains

The implementation of two-phase immersion cooling has yielded impressive results in terms of energy consumption. Microsoft’s data indicates a reduction in server power usage ranging from 5% to 15%.

Investigations into liquid immersion cooling for high-performance computing applications, including AI, confirmed a 5% to 15% reduction in power consumption per server.

Comparative Efficiency

Other companies, such as Submer, claim even greater energy savings – up to 50% – alongside a 99% reduction in water usage and an 85% decrease in space requirements.

Enhanced Reliability and Uptime

For cloud providers, the ability to maintain server operation during peak demand is paramount. Liquid immersion cooling provides the flexibility to handle these “bursty workloads” and ensure consistent uptime, even when servers are heavily taxed.

As Marcus Fontoura, a vice president on Microsoft’s Azure team, explains, “Immersion cooling gives us more flexibility to deal with these burst-y workloads,” particularly during periods of high activity like peak meeting times for Microsoft Teams.

The Environmental Impact of Data Centers

Data centers are a fundamental component of the modern internet infrastructure, supporting a vast array of tech-enabled services. However, this reliance comes with a significant environmental cost.

Alexander Danielsson, an investment manager at Norrsken VC, highlighted this concern, stating, “Data centers power human advancement… However, the environmental footprint of the industry is growing at an alarming rate.” The increasing demand for computing power, driven by technologies like AI and IoT, will only exacerbate this issue.

Underwater Data Center Solutions

Beyond utilizing experimental liquids for server cooling, an alternative approach involves submerging data centers directly into the ocean. This method is being explored by companies seeking to reduce the substantial power consumption associated with traditional cooling systems.

Microsoft has been actively operating an underwater data center for the past two years. This technology was notably showcased as part of the company’s efforts to accelerate the search for a COVID-19 vaccine during the previous year.

Deployable and Sustainable Computing

These pre-fabricated data centers, designed to the size of shipping containers, offer on-demand scalability. They can function for extended periods at significant depths beneath the ocean’s surface, providing sustainable, efficient, and powerful computing capabilities, according to Microsoft.

The principles behind this liquid cooling initiative closely align with Microsoft’s Project Natick. This project investigates the feasibility of underwater data centers that are rapidly deployable and capable of operating for years on the seabed, sealed within submarine-like structures, without requiring on-site human intervention.

Cooling Mechanisms

Unlike engineered fluids used in some liquid cooling systems, these underwater data centers utilize nitrogen-filled air. Servers are cooled through the use of fans and a heat exchanger that circulates seawater through a sealed enclosure.

Several startups are also actively pursuing the development of ocean-based data center cooling solutions.

Nautilus Data Technologies

Nautilus Data Technologies, for example, has secured over $100 million in funding (as reported by Crunchbase) to create a network of data centers located on the ocean floor. Currently, the company is developing a project near Stockton, California, integrated with a sustainable energy initiative.

Microsoft aims to replicate the advantages of ocean cooling on land with its double-immersion cooling technology. As stated by Microsoft’s Alissa, “We brought the sea to the servers rather than put the datacenter under the sea.”