Google's Liquid Cooling

It’s very odd when mainframes (S/3x0, Cray, yadda yadda) have been extensively water-cooled for over 50 years, and super-dense HPC data centers have used liquid cooling for at least 20, to hear Google-scale data center design compared to PC hobbyist rigs. Selective amnesia + laughably off-target point of comparison.

[bri3d pointed out that I missed an element of this. There is a transfer between rack level and machine level coolant which makes this far less novel than I had initially understood. See their direct comment to this]

I posed this further down in a reply-to-a-reply but I should call it out a little closer to the top: The innovation here is not “we are using water for cooling”. The innovation here is that they are direct cooling the servers with chillers that are outside of the facility. Most mainframes will use water cooling to get the heat from the core out to the edges where traditional where it can be picked up by the typical heatsink/cooling fans. Even home PCs do this by moving the heat to a reservoir that can be more effectively cooled.

What Google is doing is using the huge chillers that would normally be cooling the air in the facility to cool water which is directly pumped into every server. The return water is then cooled in the chiller tower. This eliminates ANY air based transfer besides the chiller tower. This is one being done a server or a rack.. its being done on the whole data center all at once.

I am super curious how they handle things like chiller maintenance or pump failures. I am sure they have redundancy but the system for that has to be super impressive because it can’t be offline long before you experience hardware failure!

[Edit: It was pointed out in another comment that AWS is doing this as well and honestly their pictures make it way clearer what is happening: https://www.aboutamazon.com/news/aws/aws-liquid-cooling-data...]

So every time they plug in a server they also plug in water lines?

[I am not a current Google Employee so my understanding of this is based on externally written articles and “leap of faith” guestimation]

Yes. A supply and return line along with power. Though if I had to guess how its setup this would be done with some super slick “it just works” kind of mount that lets them just slide the case in and lock it in place. When I was there almost all hardware replacement was made downright trivial so it could just be more or less slide in place and walk away.