Driven by aggressive technology scaling and sub-wavelength lithography, there has been a marked increase in the variability of process technology parameters. In addition, due to increased power density and stricter thermal envelopes, environmental parameter variability (e.g., temperature and voltage variation) increases as well. While a significant body of work exists for characterizing performance and power consumption in the presence of process-driven variability at the interface between physical-gate levels, these effects need to be modeled at higher levels of abstraction as well. In support of a complete probabilistic design flow, high-level modeling of variability effects is needed for determining design choices that are most likely to meet initial design constraints. In this talk, I will discuss our work on modeling the effects of process variation at microarchitecture and system level and show that a design style relying on multiple voltage-frequency islands (VFIs) copes in a more robust manner with the effect of process technology parameter variation. Our results show that modeling process variation effects at system level provides a 145X speedup compared to full Monte Carlo simulation. Furthermore, VFI systems can be up to 7% faster at the same power budget, or 24% more power efficient with the same baseline performance. Finally, for systems with generic topologies, a VFI design style is shown to potentially double the yield for both latency-constrained and throughput-constrained applications.

BIOGRAPHY

Diana Marculescu is an Associate Professor of Electrical and Computer Engineering at Carnegie Mellon University. She received her M.S. in Computer Science from “Politehnica” University of Bucharest, Romania in 1991 and her Ph.D. in Computer Engineering from University of Southern California in 1998. She is the recipient of a National Science Foundation Faculty Career Award (2000-2004), an ACM-SIGDA Technical Leadership Award (2003), the Carnegie Institute of Technology George Tallman Ladd Research Award (2004), and a Best Paper Award from IEEE Asia South-Pacific Design Automation Conference (ASPDAC 2005). Diana Marculescu was an IEEE-Circuits and Systems Society Distinguished Lecturer (2004-2005), is currently the Chair of the ACM Special Interest Group on Design Automation (SIGDA) and a member of IEEE. Her research interests include VLSI/computer architecture, energy- and reliability-aware computing, CAD tools for low power systems and emerging technologies.