Keeping it cool. After submerging a data centre in the North sea, Microsoft now submerges its servers in so called ‘bath tubs’
Microsoft is once again turning to liquid cooling for its hardware infrastructure, after it begun submerging its servers in so called ‘bath tubs’ of ‘boiling liquid.’
Microsoft announced the two-phase immersion cooling development this week, as it seeks improve the performance and energy efficiency of server racks in data centres.
Redmond said is testing the submerged servers for internal communications, in a data centre on the eastern bank of the Columbia River.
“Emails and other communications sent between Microsoft employees are literally making liquid boil inside a steel holding tank packed with computer servers…” Microsoft said.
The boiling liquid is not quite water it seems, as unlike water, the fluid inside th tank is harmless to electronic equipment and engineered to boil at 122 degrees Fahrenheit, 90 degrees lower than the boiling point of water.
“The boiling effect, which is generated by the work the servers are doing, carries heat away from laboring computer processors,” said Microsoft. “The low-temperature boil enables the servers to operate continuously at full power without risk of failure due to overheating.”
Microsoft said that inside the tank, the vapor rising from the boiling fluid contacts a cooled condenser in the tank lid, which causes the vapor to change to liquid and rain back onto the immersed servers, creating a closed loop cooling system.
“We are the first cloud provider that is running two-phase immersion cooling in a production environment,” said Husam Alissa, a principal hardware engineer on Microsoft’s team for data centre advanced development in Redmond, Washington.
Microsoft said that the production environment deployment of two-phase immersion cooling is the next step in Microsoft’s long-term plan to keep up with demand for faster, more powerful data centre computers at a time when reliable advances in air-cooled computer chip technology have slowed.
“Air cooling is not enough,” said Christian Belady, distinguished engineer and vice president of Microsoft’s data centre advanced development group in Redmond.
“That’s what’s driving us to immersion cooling, where we can directly boil off the surfaces of the chip,” he said.
“Liquid cooling enables us to go denser, and thus continue the Moore’s Law trend at the data centre level,” he said.
“It’s essentially a bath tub,” Belady told The Verge.
“The rack will lie down inside that bath tub, and what you’ll see is boiling just like you’d see boiling in your pot,” Belady said. “The boiling in your pot is at 100 degrees Celsius, and in this case it’s at 50 degrees Celsius.”
This development comes after Microsoft built up its liquid cooling expertise with its Project Natick, which submerged an data centre in the North sea.
Microsoft had sunk its second undersea data centre near the Orkney islands back in June 2018, and the Project Natick team spent the subsequent time monitoring and recording the performance of the subsea data centre.
Microsoft raised that second data centre in July 2020.
The idea was that a sealed container on the ocean floor could provide ways to improve the overall reliability of data centres. By placing data centres underwater, it would solve the problem of cooling the servers.
On land, corrosion from oxygen and humidity, temperature fluctuations and bumps and jostles from people who replace broken components are all variables that can contribute to equipment failure.
But Microsoft found the undersea data centre experiencing a lower failure rate than a conventional data centre.
Microsoft’s undersea data centre was essentially a white cylinder containing 12 racks containing a total of 864 servers inside, and was build to survive on the sea floor off the coast of the Orkney Islands in Scotland for up to five years.
But it should be noted that this is not the first time Microsoft has done this.
Back in 2016, Microsoft sank its first Project Natick data centre off the coast of Seattle for a period of four months.