20mm fans aren’t used in server cooling applications. You must be thinking of 40mm fans.

Going from 40mm fans to 80mm fans will not take energy usage from 25% to 1-2%. They must have taken an extreme example to compare against. What they’re doing is cool, but this is a marketing exaggeration targeted at people who aren’t familiar with the space.

Oxide also isn’t the only vendor using form factors other than 1U or focusing on high density configurations. Using DC power distribution is also an increasingly common technique.

To be honest, a lot of this feels like Apple-esque marketing where they show incredible performance improvements, but the baseline used is something arbitrary.

Our claim is not that just switching fans drops from 25% to 1-2%. We are claiming that the rack has very low energy usage, and we like to talk about the fans as one part of that reason because it's very visceral and easy to understand.

I think 1U was poorly optimized for scale, and thus bigger chassis in a rack could use bigger heatsinks and fans at lower speeds instead of small screamers.