“GreenDroid: An Architecture for the Dark Silicon Era”

Wednesday, August 10, 2011 - 9:20am

Thursday, August 11, 2011
1:30 PM
Computer Science Conference Room, Harold Frank Hall, Room 1132

HOST: Fred Chong, Professor of Computer Science

SPEAKER: Michael Taylor, Assistant Professor of Computer Science & Engineering, UC San Diego

Title: “GreenDroid: An Architecture for the Dark Silicon Era”


The Dark Silicon Era kicked off with the transition to multicore and will be characterized by a wild chase for seemingly ever-more insane architectural designs. At the heart of this transformation is the utilization wall, which states that, with each new process generation, the percentage of transistors that a chip can switch at full frequency is dropping exponentially due to power constraints. This has led to increasingly larger and larger fractions of a chip’s silicon that must remain passive, or dark.

Our research attacks this dark silicon problem directly through a set of energy-saving accelerators, called Conservation Cores, or c-cores. C-cores are a post-multicore approach that constructively uses dark silicon to reduce the energy consumption of an application by 10x or more. To examine the utility of c-cores, we are developing GreenDroid, a multicore chip that targets the Android mobile stack. Our mobile application processor prototype targets a 32-nm process and is comprised of hundreds of automatically generated, specialized, patchable c-cores. These cores target specific Android hotspots, including the kernel. Our preliminary results suggest that we can attain an average 7x improvement in energy efficiency using a modest 7 mm2 of silicon.


Michael B. Taylor is an Assistant Professor of Computer Science and Engineering at UC San Diego. His research interests focus around the design of novel computing artifacts. His recent projects include Kremlin, a tool best described as “like gprof, but for parallelization”; GreenDroid, jointly led with Steven Swanson; and SD-VBS, a vision benchmark suite. As a PhD student at MIT, Michael was the lead architect of the 16-core MIT Raw processor, which was later commercialized into the 100-core Tilera chips. Prior to that, he co-authored the first version of the Connectix VirtualPC x86-to-PowerPC translator, and hacked microkernels at Apple. He received the NSF CAREER Award in 2009, a PhD from MIT in 2007, and an AB from Dartmouth College in 1996. He has been writing code for 86% of his life.