Server racks bring the cooling to a boil
Obviously, Microsoft's engineers have a thing for liquids.
In 2015, for example, they sank a small data center in the Atlantic off the Scottish Orkney Islands.
And not because they wanted to get rid of it, but because they hoped to be able to use the cold seawater to cool the computers.
Five years later you lifted the computer container, now densely populated by mussels, back to the surface and called the experiment called Project Natick a success.
But while the cooling in this project was still done by nitrogen gas, which gave off the heat from the microprocessors to the sea via heat exchangers, in a new Microsoft project entire server racks are immersed in a cooling liquid.
In pictures published by the company on Tuesday, this looks confusing at first glance: the liquid that flows around the circuit boards appears to be boiling.
And actually it does, but not at 100 degrees Celsius, because it's not water that the engineers immerse the computers in.
That would also be counterproductive, since water is known to conduct electricity and would instantly lead to short circuits.
A closed cycle
The choice therefore fell on a liquid not specified by Microsoft, but non-conductive, according to "The Verge" based on fluorocarbons, which have a much lower boiling point than water, namely 50 degrees Celsius.
In order to be able to take advantage of their properties, the servers are sunk in hermetically sealed tanks, in which the boiling coolant can evaporate and condense on condenser plates embedded in the lid, and then rain back into the tank in the form of drops.
Microsoft technicians inspect the new server tank.
The capacitors are clearly visible on the cover
The unusual cooling method is necessary because computer chips require more and more electrical energy and thus produce more and more waste heat, explains Microsoft manager John Roach.
Because the chips contain ever more and ever smaller assemblies, the power consumption of computer processors has risen from around 150 watts to more than 300 watts.
Graphics processors, which are also often used in data centers, would even convert more than 700 watts per chip.
The previously common air cooling would no longer be sufficient, said Christian Belady, vice president of Microsoft's development group for data centers in Redmond.
“That's what drives us to immersion cooling, in which we can boil the heat directly from the surface of the chip.” Because liquids dissipate heat better than air, this system could also put the computers closer together, meaning more computing power per square meter focus.
Microsoft primarily uses the mini-data center built for the test in the tank to buffer short-term peak loads, for example when many employees dial into team conferences at 1 p.m. and 2 p.m. at the same time.
Ultimately, the technology should help save energy to operate data centers more cheaply.
It is also hoped to be able to reduce the failure rates and thus the maintenance effort for the servers through the liquid cooling.
As a possible application for the new technology, the group names data centers, which, like oil tanks, could be buried under 5G radio masts in the middle of city centers.
However, it will be some time before that happens.
For the next few months, the engineers have initially set out to try out a series of tests to see whether their idea is suitable for series production.