Dark Silicon arises because per-transistor power has stopped scaling while transistor density continues to grow. The result is the “utilization wall” that prevents processors from using all their transistors at once. We (in collaboration with Dr. Michael Taylor) wrote one of the earliest peer-reviewed architecture papers to describe of the utilization wall and to propose specialization as an architectural solution.
To demonstrate the value of this approach, developed a prototype mobile application processor called GreenDroid that leverage “dark silicon” to dramatically reduce energy consumption in smartphones. GreenDroid will provide many specialized processors targeting key portions of the Android smartphone platform.
We built GreenDroid with a custom-built, fully-automated toolchain that generates energy-efficient “conservation cores” (C-Cores) from application source code. The resulting specialized circuits can deliver up to 18x increases in energy efficiency without sacrificing performance. C-cores also incorporate focused reconfigurability that allows them to adapt to small changes in the target application while still realizing efficiency gains.
Publications
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Exploring Energy Scalability in Coprocessor-Dominated Architectures for Dark Silicon
ACM Trans. Embed. Comput. Syst. 13(4s):130:1-130:24, April 2014. -
QsCores: Configurable Co-processors to Trade Dark Silicon for Energy Efficiency in a Scalable Manner
Proceedings of The 44th International Symposium on Microarchitecture, 2011. -
An Evaluation of Selective Depipelining for FPGA-based Energy-Reducing Irregular Code Coprocessors
2011 International Conference on Field Programmable Logic and Applications, 2011. -
GreenDroid: Exploring the next evolution in smartphone application processors
Communications Magazine, IEEE 49(4):112-119, April 2011. -
Reducing the Energy Cost of Irregular Code Bases in Soft Processor Systems
Field-Programmable Custom Computing Machines, Annual IEEE Symposium on:210-213, 2011. -
The GreenDroid Mobile Application Processor: An Architecture for Silicon's Dark Future
Micro, IEEE 31(2):86-95, march-april 2011. -
Efficient Complex Operators for Irregular Codes
Proceedings of the 17th IEEE International Symposium on High-Performance Computer Architecture Conference (HPCA 17), 2011. -
Conservation cores: reducing the energy of mature computations
Proceedings of the fifteenth edition of ASPLOS on Architectural support for programming languages and operating systems, 2010. -
GreenDroid: A Mobile Application Processor for a Future of Dark Silicon
Proceedings of HotChips, 2010.