Institute Lecture by Prof. Murali Annavaram @2pm

Location: Faculty Hall

Indian Institute of Science

Institute Lecture

Speaker: Prof. Murali Annavaram
Smt. Rukmini and Sri. Gopalakrishnachar Visiting Chair Professor,
University of Southern California, USA

Title: Energy Efficient Computing in the Climate Crisis Era

Date: Friday, February 10, 2023

Time: 2:00 PM

Venue: Faculty Hall, Indian Institute of Science

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The detrimental impact of climate crisis on a society’s wellbeing is now clear. Reducing the energy consumption, and hence the carbon footprint, has been a pressing goal for the computing industry. For decades computing technology has been blessed with Dennard scaling and Moore’s law which have capped energy consumption growth. With these scaling laws facing massive hurdles, computer architects are now faced with the baffling task of optimizing the energy usage of systems across diverse usage scenarios. A server that is optimized for parallel computing performs exceedingly poorly for sequential computations. And, a server that runs efficiently during peak utilization performs poorly during low utilization. We present two path-breaking techniques to improve energy efficiency in the presence of unpredictable application demands. We first present Energy Per Instruction (EPI) throttling, a mechanism for varying the amount of energy expended to process instructions according to the amount of available parallelism. As irregular parallelism became dominant compute paradigm, EPI throttling became the foundation for energy efficient computing, as evinced in Intel’s Turbo Boost. We then present KnightShift that addresses the lack of server energy proportionality. For decades server designers focused on improving the energy efficiency of servers at peak utilization. As such servers burn disproportionate amounts of energy at intermediate utilization. KnightShift couples a high-performance server with a low-power compute node called the Knight to achieve near-perfect energy proportionality. KnightShift’s advocacy of heterogeneous system design is now widely used in industry, such as the ARM’s Big.LITTLE design.


Murali Annavaram is a Dean’s Chair Professor in the ECE and CS departments at USC. He currently holds the Smt. Rukmini – Shri. Gopalakrishnachar Visiting Chair Professorship at IISc. He is the founding director of the REAL@USC-Meta centre that is focused on research and education in AI, and the co-PI on the NSF DISCoVER Expedition on superconducting computing. His group’s KnightShift research won the 2012 IEEE Micro Top Picks’ most influential research paper award. His work at Intel lead to the first 3D microarchitecture design, and also influenced Intel’s TurboBoost technology. Murali co-authored Parallel Computer Organization and Design, a widely used textbook in computer architecture. He is a Fellow of IEEE and Senior Member of ACM.

Host Faculty: Prof. Rajesh Sundaresan, Dean, EECS