Google's Liquid Cooling

Relevant.

OVH has been using liquid cooling for many years:

https://blog.ovhcloud.com/new-hybrid-immersion-liquid-coolin...

https://www.youtube.com/watch?v=S_DHJcQpumI

And yet their claimed PUE is 1.26 which is pretty bad. One way to characterize that overall PUE figure is they waste 3x as much on overhead as Google (claimed 1.09 global PUE) or Meta (1.08).

Your linked articles are about immersion cooling, which is "liquid cooling," I suppose, but a very different thing. Do OVH actually use immersion cooling in production? This seems like a "labs" product that hasn't been fully baked yet.

OVH _do_ definitely use traditional water-loop/water-block liquid cooling like Google are presenting, described here: https://blog.ovhcloud.com/understanding-ovhclouds-data-centr... and visually in https://www.youtube.com/watch?v=RFzirpvTiOo , but while it looks very similar architecturally their setup seems almost comically inefficient compared to Google's according to their PUE disclosures.

10 years ago, OVH datacenter SBG1 was below 1.1 with a mixture of natural convection + liquid cooling. But I have not been following in the latest years.

Based on how their data centers burn down, they don't even use liquid in their fire suppression systems.