Google's Liquid Cooling

Hyper-scale data centers normally need not be concerned with power density, and their designers might avoid density because of the problems it causes. Arguably modern HPC clusters that are still concerned about density are probably misguided. But when it comes to ML workloads, putting everything physically close together starts to bring benefits in terms of interconnectivity.

LOLWUT? Hyperscalers and HPC data centers have been very concerned about power and thermal density for decades IME. If you're just running web sites or VM farms, sure keep racks cooler and more power efficient. But for those that deeply care about performance, distance drives latency. That drives a huge demand to "pack things closely" and that drives thermal density up, up, up. "Hot enough to roast a pig" was a fintech data center meme of 20 years go, back at 20kW+ racks. Today you're not really cooking until you get north of 30kW.

Name a hyper-scale data center where the size and shape suggests that power density ever entered the conversation.

My impression is a lot of modern data centres are total-power-constrained, but not really space-constrained.

At least, if you look at them on streetview a lot of them seem to be in the middle of nowhere, surrounded by miles of undeveloped scrubland. If Google's Henderson, NV data centre [1] needed more space they could simply buy out the adjacent car wrecking yard or pet crematorium, or reconsider the gigantic gatehouse and vast expanses of beige gravel.

Even in Belgium, with its higher population density [2] the car park is bigger than the data centre.

The layout makes me think they were told they could only have a certain amount of power, but essentially as much land as they needed. So they're concerned about power and thermals, but maybe not about power and thermal density so much.

[1] https://www.google.com/maps/place/Google+Data+Center+-+Hende... [2] https://www.google.com/maps/place/Google+Data+Center/@55.557...