Air-assisted direct liquid cooling: an overlooked option

The steady rise of server power levels is one of the major data center trends over the past 10 years, and one which Uptime Intelligence has discussed regularly (see Silicon heatwave: the looming change in data center climates). The interplay of underlying forces that drive this escalation are complex, but the net effect is clear: with every new semiconductor technology generation, server silicon is pushing air cooling equipment close to its operational limits. Standard-setting industry body ASHRAE’s 2021 thermal guidelines warned of temperature restrictions for some future servers (see New ASHRAE guidelines challenge efficiency drive). More recently, another catalyst to this rising power consumption is the industry’s ongoing efforts in training large machine learning models, spearheaded by generative AI applications.

These developments have, once again, brought the issue of high-powered racks to the fore and with it a renewed interest in the benefits of direct liquid cooling (DLC) in data centers. There is a significant opportunity to maximize compute power using DLC, both in terms of IT capacity and outright server performance.