Abstract
Continuous advances in manufacturing technologies are enabling the development of more powerful and compact high-performance computing servers made of 2D and 3D multi-processor system-on-chip (MPSoC) designs. However, 3D stacking originates higher power and heat densities, leading to degraded performance in high-performance computing if cooling is not handled properly at all levels of abstraction. In this talk, I first describe a new framework for detailed system-level thermal modeling of 2D/3D MPSoC including inter-tier microchannels. Then, I will describe a new family of global hardware/software temperature controllers for energy-efficient 2D/3D MPSoC cooling. These novel controllers include a thermal-aware job scheduler, which balances the temperature across the system to maximize cooling efficiency. Furthermore, this new generation of system-level temperature balancing controllers forecast maximum system temperature, and uses this forecast to proactively set the cooling system. Hence, the proposed controller avoids over- or under-cooling due to delays in reacting to temperature changes. The experiments on modeled 2- and 4-layered 3D MPSoCs show that this proposed global cooling controller prevents enables up to 80% energy savings with respect to state-of-the-art computing systems designs in future datacenters. Finally, I will outline how the combination of inter-tier liquid cooling technologies and 3D computing architectures design can overcome the problem of dark silicon and energy proportionality deployment in future generations of many-core servers and datacenters.

Short Bio
David Atienza is associate professor of EE and director of the Embedded Systems Laboratory (ESL) at EPFL, Switzerland. He received his MSc and PhD degrees in computer science and engineering from UCM, Spain, and IMEC, Belgium, in 2001 and 2005, respectively. His research interests focus on system-level design methodologies for 2D and 3D multi-processor Systems-on-Chip (MPSoC) and low-power embedded systems. He has co-authored more than 200 publications in prestigious journals and international conferences, several book chapters and six U.S. patents.
He has earned several best paper awards at top venues in electronic design automation and computer and system engineering; he received the IEEE CEDA Early Career Award in 2013, the ACM SIGDA Outstanding New Faculty Award in 2012 and a Faculty Award from Sun Labs at Oracle in 2011. He is a Distinguished Lecturer (2014-2015) of the IEEE CASS, and was GOLD member of the Board of Governors of IEEE CASS from 2010 to 2012. He is Senior Member of IEEE and ACM.