Towards Thermally-Aware Design of 3D MPSoCs with Inter-Tier Cooling

Mohamed M. Sabry, Arvind Sridhar, David Atienza, Yuksel Temiz, Yusuf LeblebicI, Sylwia Szczukiewicz, Navid Borhani, John R. Thome, Thomas Brunschwiler, and Bruno Michel
Proc. of Design, Automation and Test in Europe (DATE ’11), ACM and IEEE Press, Grenoble, France, March 14-18, 2011.
New tendencies envisage 3D Multi-Processor System-On-Chip (MPSoC) design as a promising solution to keep increasing the performance of the next-generation highperformance computing (HPC) systems. However, as the power density of HPC systems increases with the arrival of 3D MPSoCs, supplying electrical power to the computing equipment and constantly removing the generated heat is rapidly becoming the dominant cost in any HPC facility. Thus, both power and thermal/cooling implications play a major role in the design of new HPC systems, given the energy constraints in our society. Therefore, in this work we propose a new holistic thermally-aware design. This paper presents the exploration of novel cooling technologies, as well as suitable thermal modeling and system-level design methods, which are all necessary to develop 3D MPSoCs with inter-tier liquid cooling systems. As a result, we develop energy-efficient run-time thermal control strategies to achieve energy-efficient cooling mechanisms to compress almost 1 Tera nano-sized functional units into one cubic centimetre with a 10 to 100 fold higher connectivity than otherwise possible. The proposed thermally-aware design paradigm includes exploring the synergies of hardware-, software- and mechanical-based thermal control techniques as a fundamental step to design 3D MPSoCs for HPC systems. Our management strategy prevents the system from surpassing the given threshold temperature while achieving up to 67% reduction in cooling energy and up to 30% reduction in system-level energy in comparison to setting the flow rate at the maximum value to handle the worst-case temperature.