Microsoft now plunges servers into liquid baths

Microsoft is starting to immerse its servers in liquid to improve their performance and energy efficiency. A Serbian servers are now used for production loads in a liquid bath. This immersion process has been in the industry for several years, but Microsoft claims that it is “the first cloud supplier to use two-phase immersion cooling in a manufacturing environment.”

The cooling works by completely immersing server shelves in a specially designed non-conductive liquid. The fluorocarbon-based liquid works by removing heat as it hits the components directly and the liquid reaches a lower boiling point (122 degrees Fahrenheit or 50 degrees Celsius) to condense and fall back into the bath as a rain liquid. This creates a closed loop cooling system that reduces costs, as no energy is required to move the liquid around the tank, nor is any cooler needed for the condenser.

Image: Microsoft

“It’s essentially a bath,” explains Christian Belady, vice president of Microsoft’s advanced data center development team, in an interview with The edge. ‘The rack will lie in the bath, and what you see boils just like you would cook in your pot. The boiling point in your pot is 100 degrees Celsius, and in this case it is 50 ° C. “

This type of liquid cooling has been used by cryptocurrencies in recent years to exploit bitcoin and other cryptocurrencies. This method has inspired Microsoft to test its use over the past few years, to test it against the demand for clouds and intensive workload for applications such as machine learning.

Most data centers are currently air-cooled, using and cooling outdoors by dropping it to evaporation to temperatures below 35 degrees Celsius. This is known as swamp cooling, but it uses a lot of water in the process. This new liquid bath technique is designed to reduce water usage. “It will probably eliminate the need for water consumption in data centers, so this is really an important thing for us,” says Belady. “It’s really just about reducing the impact on everywhere we go.”

Image: Microsoft

With this server team, Microsoft can also pack hardware, which will reduce the amount of space required in the long run compared to traditional air cooling. Microsoft initially tested it with a small internal production workload, and plans to use it more widely in the future. “It’s in a small data center and we’re looking at the value of one rack,” says Belady. “We have a phased approach, and our next phase is coming up soon with multiple shelves.”

Microsoft will primarily study the reliability implications of this new cooling and what types of burst workloads it may even help with the demand for clouds and AI. “We expect much better reliability. Our work with the Project Natick program a few years ago showed the importance of eliminating humidity and oxygen from an environment, ”explains Belady.

Image: Microsoft

Project Natick saw Microsoft drop an entire data center to the bottom of the Scottish Sea, storing 864 servers and 27.6 petabytes in the water. The experiment was a success, and Microsoft had only one-eighth of the failure rate of a land-based data center. “What we expect with immersion is a similar trend, because the fluid displaces the oxygen and the humidity, and both create corrosion … and these are the things that cause failure in our systems,” says Belady.

Part of this work is also related to Microsoft’s environmental promise to address water scarcity. The company is committed to replenishing even more water than it uses for its global operations by 2030. This includes Microsoft using a local rainwater collection system at its offices and collecting condensate from air conditioners to water plants. Nevertheless, in 2019, Microsoft extracted nearly 8 million cubic meters of water from municipal systems and other local sources, compared to just over 7 million in 2018.

Microsoft’s effort to address water use will be extremely challenging, given the trend towards more water use, but projects such as two-phase immersion will certainly help if applied more widely. “Our goal is to reach zero water consumption,” says Belady. “That’s our benchmark, so that’s what we’re working on.”