Holistic Rack-to-Processor Power and Thermal Co-Design for Future Servers and Data Centers

Abstract: All electrical energy going into a data center must eventually be rejected as heat to the environment through a cooling system. Data center cooling can be energy intensive; it may account for up to 33—40% of overall data center energy usage and consumes hundreds of billions of gallons of fresh water per year. With chip manufacturing processes reaching fundamental limitations for scaling ever-smaller transistors, it is anticipated that processor power will rise, increasing data center power density. In addition, recent weather events have caused extreme heat, droughts, and other challenges, limiting the availability of sometime scarce resources for cooling purposes. Cooling energy for data centers is significant today, and these trends make it an even more important energy area in the future. In this talk, I will discuss our highly collaborative work to develop transformational, highly efficient, and reliable cooling technologies for data centers. We target to reduce total cooling energy expenditure to less than 5% of a typical data center’s IT load at any time and any U.S. location for a high-density compute system. This reduction of data center cooling energy will reduce the operational CO₂ footprint of data center operations. We achieve these goals by working with key stakeholders such as Nokia Bell Labs, Meta, and Wiwynn to dramatically reduce the thermal resistance of heat rejection (< 0.01 K/W), allowing for coolants to exist at temperatures much closer to operating temperatures of the latest generation of chips (targeting <10°C difference between chip and coolant). This results in more efficient heat removal from the facility. I will discuss our solutions and design methods which enable high volumetric compute density systems of >80kW/m³, equivalent to about >3kW per server, and how these methods can be used to develop next generation data centers which optimize for energy efficiency. 

BIO:  Dr. Nenad Miljkovic is the Founder Professor of Mechanical Science and Engineering at the University of Illinois at Urbana-Champaign (UIUC). He has courtesy appointments in Electrical and Computer Engineering, and the Materials Research Laboratory. He is the Director of the Air Conditioning and Refrigeration Center (ACRC), which is supported by 21 industrial partners. His group’s research intersects the multidisciplinary fields of thermo-fluid science, interfacial phenomena, scalable nanomanufacturing, and renewable energy. He is a recipient of the NSF CAREER Award, the ACS PRF DNI Award, the ONR YIP Award, the ASME ICNMM Young Faculty Award, the ASME Pi Tau Sigma Gold Medal, the CERL R&D Technical Achievement Award, the US Army Corps of Engineers ERDC R&D Achievement Award, the SME Young Faculty Award, the Bergles-Rohsenow Young Investigator Award in Heat Transfer, the ASME EPPD Early Career Award, and is an ASME Fellow.