Energy-Driven Hardware Adaptations for Multimedia Applications

Tuesday April 29, 2003
Hamerschlag Hall 1112
4:30pm

Sarita Adve
University of Illinois - Urbana-Champaign

Mobile systems primarily processing multimedia data are becoming increasingly important. The design of such systems must consider demanding, dynamic, and multidimensional resource requirements and constraints, with energy as a first-class resource. A promising approach to meeting these challenges is to design all system layers with an ability to adapt in response to system or application changes. The Illinois GRACE (Global Resource Adaptation through CoopEration) project is developing an integrated cross-layer adaptive system where hardware and all software layers cooperatively adapt to changes in the system and applications, seeking to maximize user satisfaction while meeting the resource constraints of energy, time, and bandwidth. This talk will give a brief overview of the GRACE project and then focus on controlling adaptation in the hardware layer to minimize energy consumption.

In the hardware layer, two sources of energy-inefficiency in modern processors are: (1) they often run faster than necessary for the application's real-time constraint, and (2) often resources stay active, consuming energy, but contributing little to performance. Recently, researchers have proposed two forms of hardware adaptation to improve energy efficiency: architecture adaptation and dynamic voltage/frequency scaling (DVS). A key to the effective use of these adaptations is the control algorithm that determines when and what to adapt. We propose (to our knowledge) the first adaptation control algorithms that integrate both architecture adaptation and DVS and address both the above sources of energy inefficiency, targeted towards multimedia applications. Our results show that the proposed algorithms are effective at reducing energy consumption in a variety of scenarios, architecture adaptation is effective with and without DVS, and addressing both sources of energy inefficiency gives significant gains. Overall, an integrated design works better than using any technique alone.

Sarita Adve is an Associate Professor in the Department of Computer Science at the University of Illinois at Urbana-Champaign. Her research interests are in computer architecture. Her current work is primarily on energy and thermal efficient systems for multimedia and communications applications, as part of the Illinois GRACE and 4-PEAC projects. Her past contributions are in the areas of memory consistency models, exploiting instruction-level parallelism (ILP) for memory system performance, and evaluation techniques for shared-memory multiprocessors with ILP processors. She led the development of the widely used RSIM architecture simulator.

Professor Adve received an Alfred P. Sloan Research Fellowship in 1998, an IBM University Partnership award in 1997 and 1998, and a National Science Foundation CAREER award in 1995. She received the Ph.D. and M.S. degrees in Computer Science from the University of Wisconsin - Madison in 1993 and 1989 respectively, and the B.Tech. degree in Electrical Engineering from the Indian Institute of Technology - Bombay in 1987. Before joining Illinois, she was on the faculty at Rice University from 1993 to 1999.