Liquid Cooling To Maintain Microsoft’s Data Centres

Huge demands on Microsoft’s data centre servers, partly driven by a surge in Microsoft Teams user numbers has led to the tech giant opting for liquid-immersion cooling.

The Challenge

Microsoft has recognised that it has now come up against the slowdown of Moore’s Law as transistor widths have shrunk to atomic scales and are reaching a physical limit, whilst the demand for faster computer processors for high performance applications such as AI has accelerated. This has meant that more electric power is now being put through the small processors used in Microsoft’s data centres, thereby increasing the heat they produce.  According to Microsoft, this means that air cooling is no longer enough to prevent the chips from malfunctioning. The demands of a huge increase in the numbers of Teams users during lockdown and the need to maintain sustainable and energy efficient data centres have also contributed to Microsoft’s decision to try liquid cooling.

Two-Phase Immersion Cooling

Since heat transfer in liquids is more efficient than air, Microsoft’s new system of two-phase immersion cooling involves immersing servers in tanks filled with an engineered fluid (from 3M) which has dielectric properties (i.e. it is an effective insulator), thereby allowing the servers to operate normally while fully immersed in the fluid. The liquid boils at 122 degrees Fahrenheit (90 degrees lower than the boiling point of water) and this boiling effect, generated by the work the servers are doing, takes the heat away from the computer processors whilst the low-temperature boil enables the servers to operate continuously at full power without risk of failure due to overheating.

The second phase of this two-phase process refers to the vapour rising from the tanks making contact with a cooled condenser in the tank lid, thereby changing it back to liquid that rains back onto the immersed servers, creating a closed-loop cooling system.

The Result

Microsoft says that the result of it becoming the “first cloud provider that is running two-phase immersion cooling in a production environment” at its datacentre in Quincy should be the ability of the company to:

– Continue the Moore’s Law trend at the datacentre level.

– Reduce power consumption.  For example, Microsoft’s trial of using liquid two-phase immersion for cooling AI showed reduced power consumption for any given server by 5 to 15 per cent.

– Increased flexibility for the efficient management of cloud resources.

– Improved efficiency and sustainability.

– The fact that the system uses a specially developed cooling fluid, and not water, gives Microsoft the ability to meet its commitment to replenish more water than it consumes by the end of the decade.

What Does This Mean For Your Business?

If your business uses Microsoft’s cloud-based services, and particularly those which involve AI and/or Teams, this switch to a new cooling technology at datacentre level should mean smooth running services with less risk of potentially costly outages and disruption going forward. For Microsoft, this may give it an advantage over cloud company competitors in terms of capacity, reliability, and sustainability credentials.