Long Term Sustainability of Differentially Reliable Systems in the Dark Silicon Era

Developed by Jason M. Allred, Dr. Sanghamitra Roy, and Dr. Koushik Chakraborty of Utah State University’s Electrical and Computer Engineering Department


Technical Summary

Rapid miniaturization of transistor devices substantially degrades both the circuit and system level reliability, increasing the cost of providing reliable execution. Offsetting that trend, software is developing greater diversity in error tolerance. For example, Differentially Reliable (DR) systems are designed with differing intrinsic reliability levels between components. DR systems can deliver a tremendous advantage in energy efficiency with the use of dark silicon, or the portion of a chip that must be powered down due to power budget constraints.

Unfortunately, asymmetric utilization of cores, differential aging degradation, and manufacturing process variation distort the critical reliability differentiation of DR system components and cause a drop in their ability to effectively provide superior energy efficiency. “Long-Term Sustainability of DR Systems in Dark Silicon” is a patent pending circuit-architectural framework guided by a feedback control, thread-to-core mapping framework that enables a DR system to retain its energy efficiency advantage throughout the lifetime of the chip.


Competitive Advantages

Researchers at Utah State University validated their design using an extensive cross-layer methodology, combining SPICE-level process variation with device-level aging analysis, circuit-level statistical timing analysis, and full system architectural simulation. The researchers demonstrated 14.4–16.3% and 26.1–31.0% sustained energy efficiency benefits for two distinct DR design techniques operating during a ten-year lifespan.


Commercial Applications

•  Multicore systems

•  Anything involving memory

•  High performance systems



•  U.S. Patent Application Publication: 2015/0100930 A1

•  Allred, J.M.; Roy, S.; Chakraborty, K., "Long term sustainability of differentially reliable systems in the dark silicon era," in Computer Design (ICCD), 2013 IEEE 31st International Conference on , vol., no., pp.70-77, 6-9 Oct. 2013  doi: 10.1109/ICCD.2013.6657027



Patent Information:
Computer Science
For Information, Contact:
Christian Iverson
Utah State University
Sanghamitra Roy Koushik Chakraborty Jason Allred