Dark Silicon (MBT)    

Professor
Michael B. Taylor

UCSD Center for Dark Silicon
 Computer Science and Engineering 
University of California, San Diego 92093

email
EBU 3b 3202 office
gchat
+1 use email phone
+1 (858) 534 7029 fax

Research Team Teaching Service Programming Team



Bio

I have been a professor in the Department of Computer Science and Engineering at the University of California, San Diego since 2005. I received a PhD in Electrical Engineering and Computer Science from MIT. I was lead architect of the 16-core MIT Raw tiled multicore processor, one of the earliest multicore processors, which was commercialized into the Tilera TILE64 architecture. I co-authored the earliest published research on dark silicon, including a paper that derives the utilization wall that causes dark silicon.

I occasionally help companies and other legal professionals evaluate their patent portfolios, and provide advice to companies leveraging the Tilera TILE64 architecture. I have broad expertise in hardware and software, and on the Bitcoin cryptocurrency. My research is funded primarily by the National Science Foundation (NSF), including the Secure and Trustworthy Cyberspace Program, and DARPA/MARCO's C-FAR, part of STARnet.

Between the gaps at school, I worked on Apple's NuKernel microkernel, and co-wrote the first version of Connectix Virtual PC, an x86-to-PowerPC dynamic translation engine, which was acquired by Microsoft. I also contributed to the ChipWrights Visual Signal Processor in its earliest stages.

I received the NSF CAREER Award in 2009 and tenure in 2012.

My research sponsors:
C-FAR Logo NSF Logo NSF logoIntel LogoAMD logo



UCSD Center for Dark Silicon



I direct the UCSD Center for Dark Silicon.

My colleagues and I were among the first to demonstrate the existence of a utilization wall which says that with the progression of Moore's Law, the percentage of a chip that we can actively use within a chip's power budget is dropping exponentially! The remaining silicon that must be left unpowered is now referred to as Dark Silicon.

Our research on Conservation Cores and GreenDroid proposes new architectures that exploit dark silicon. Our paper on the The Four Horsemen (slides) overviews the landscape of architectural approaches to addressing dark silicon. In addition to researching architectures for dark silicon, I look more broadly at sources of under-utilization in current day chips, spanning from a) power limitations because of poor CMOS scaling, b) overly large software engineering costs for parallelizing programs for multicore chips, and c) lack of parallel application domains.

My research attacks each of these problems by 1) reinventing processor design to make use of dark silicon, 2) utilizing existing cores better through better parallel software engineering tools and 3) finding new parallel application classes to put cores to work:
        
GreenDroid


The GreenDroid Mobile Applications Processor, which employs Conservation Cores to fight dark silicon.
                
Our ASPLOS 2010 paper is one of the earliest peer-reviewed architecture papers to have a cogent description of the utilization wall that causes the Dark Silicon problem, and to propose specialization as an architectural solution.

Our Hotchips 2010 work GreenDroid: A Mobile Application Processor for a Future of Dark Silicon flushes out this proposal, and is quite possibly the first published academic use of the term Dark Silicon. This was followed up with this March 2011 IEEE Micro paper. (Here is the Hotchips talk on youtube.)

Our work, Is Dark Silicon Useful? Harnessing the Four Horsemen of the Coming Dark Silicon Apocalypse, which appeared in DAC and DaSi 2012, and is followed by a paper in IEEE Micro 2013, is the first paper to overview the landscape of architectural approaches that try to address the dark silicon problem. We describe the four horsemen -- four approaches to dealing with dark silicon, each with deep-seated challenges but also unique capabilities. See the slides for a very entertaining presentation on the shrinking, dim, specialized, and deux ex machina horsemen.

              Four Horseman


Kremlin Logo
Kremlin, a tool that, given a serial program, tells you which regions to parallelize.
                
To create Kremlin, we developed a novel dynamic analysis, hierarchical critical path analysis, to detect parallelism across nested regions of the program, which connects to a parallelism planner which evaluates many potential parallelization to figure out the best way for the user to parallelize the target program.



Stingray Picture
     the San Diego Vision Benchmark Suite, which distills the emerging computer vision application class into a collection of nine benchmarks written in a research-friendly style. This work was advised by Prof. Serge Belongie, a member of UC San Diego's top-notch vision faculty.




Greatest Hits (Click to view all publications)


  1. Bitcoin and The Age of Bespoke Silicon
    (Read this for a stirring account of the Bitcoin mining community that
    heralds a new age of hardware innovation tailored to emerging application domains)

    Michael Bedford Taylor
    International Conference on Compilers, Architecture and Synthesis for Embedded Systems (CASES), Sept 2013. (Talk) (Paper) (bib)

  2. A Landscape of the New Dark Silicon Design Regime
    Michael Taylor.
    IEEE Micro, Sep/Oct 2013. (pdf) (bib) DATE 2014 talk.

  3. Is Dark Silicon Useful?
    Harnessing the Four Horsemen of the Coming Dark Silicon Apocalypse

    (Cite this for first synthesis of approaches to attacking Dark Silicon.)
    Michael B. Taylor
    Design Automation Conference (DAC), June 2012. (pdf) (bib) (slides).
    Also presented at the Dark Silicon Workshop (DaSi) 2012.

  4. Conservation Cores: Reducing the Energy of Mature Computations.
    (Cite this for first peer-reviewed Utilization Wall & Dark Silicon Analysis.
    Also for heterogeneity as a solution to dark silicon problem.)

    Ganesh Venkatesh, John Sampson, Nathan Goulding, Saturnino Garcia, Slavik Bryskin, Jose Lugo-Martinez, Steven Swanson, and Michael Bedford Taylor.
    Architectural Support for Programming Languages and Operating Systems (ASPLOS), March 2010. (pdf) (talk pdf, talk ppt) (bib)

  5. GreenDroid: A Mobile Application Processor for a Future of Dark Silicon
    (Cite this for dark silicon's impact on multicore scaling.
    Also, for the GreenDroid massively heterogeneous processor.)

    Nathan Goulding, Jack Sampson, Ganesh Venkatesh, Saturnino Garcia, Joe Auricchio, Jonathan Babb, Michael Bedford Taylor and Steven Swanson.
    Proceedings of HOTCHIPS, August 2010. (pdf) (talk ppt) (bib) (youtube)

  6. The GreenDroid Mobile Application Processor: An Architecture for Silicon's Dark Future
    Nathan Goulding-Hotta, Jack Sampson, Ganesh Venkatesh, Saturnino Garcia, Joe Auricchio, Po-Chao Huang, Manish Arora, Siddhartha Nath, Jonathan Babb, Steven Swanson, and Michael Bedford Taylor.
    IEEE Micro, March 2011. (pdf) (bib)

  7. Kremlin: Rebooting and Rethinking gprof for the Multicore Age (Cite this for Kremlin.)
    (aka Automatic Parallelism Planning and Discovery with Kremlin)
    Saturnino Garcia, Donghwan Jeon, Chris Louie, and Michael Bedford Taylor.
    Programming Language Design and Implementation (PLDI), June 2011. (pdf) (bib)

  8. SD-VBS: The San Diego Vision Benchmark Suite.
    Sravanthi Kota Venkata, Ikkjin Ahn, Donghwan Jeon, Anshuman Gupta, Christopher Louie, Saturnino Garcia, Serge Belongie, and Michael Bedford Taylor.
    IEEE International Symposium on Workload Characterization (IISWC), October 2009. (pdf) (Download SD-VBS) (bib)

  9. Evaluation of the Raw Microprocessor:
    An Exposed-Wire-Delay Architecture for ILP and Streams

    by Michael B Taylor, Walter Lee, Jason Miller, David Wentzlaff, Ian Bratt, Ben Greenwald, Henry Hoffmann, Paul Johnson, Jason Kim, James Psota, Arvind Saraf, Nathan Shnidman, Volker Strumpen, Matt Frank, Saman Amarasinghe, and Anant Agarwal.
    Proceedings of the International Symposium on Computer Architecture (ISCA), June 2004. (pdf) (bib)

  10. The Raw Microprocessor:
    A Computational Fabric for Software Circuits and General Purpose Programs
    ,
    by Michael B Taylor, Jason Kim, Jason Miller, David Wentzlaff, Fae Ghodrat, Ben Greenwald, Henry Hoffman, Jae-Wook Lee, Paul Johnson, Walter Lee, Albert Ma, Arvind Saraf, Mark Seneski, Nathan Shnidman, Volker Strumpen, Matt Frank, Saman Amarasinghe and Anant Agarwal.
    IEEE Micro, March/April 2002. (pdf) (bib)

  11. Scalar Operand Networks,
    by Michael B Taylor, Walter Lee, Saman Amarasinghe, and Anant Agarwal.
    IEEE Transactions on Parallel and Distributed Systems (Special Issue on On-chip Networks) (TPDS), February 2005. (pdf) (Appendix pdf) (bib)

Recent News


Mar 2014 See my E3S Talk, entitled "A Landscape of the New Dark Silicon Regime". I gave a similar talk at DATE 2014 in Dresden, Germany.

Jan 2014Article in Data Center Knowledge discussing my Bitcoin CASES paper.

Dec 2013 I helped a reporter from the New York Times, Nathaniel Popper, as he deliberated on whether to fly to Iceland to meet a stranger and view their installation! He put together this great story on recent developments in Bitcoin mining. (I am quoted a few times.)

Oct 2013 Because of some of my Bitcoin knowledge, a few newspapers, radio shows, and a TV show interviewed me about Bitcoin, Tor and the Silk Road takedown:

Al Jazeera America
(Live National TV)

MBT on News Show Consider This with Antonio Mora

(15 min TV spot)
10/3/13
Baltimore Sun

Silk Road arrest exposes a hidden Internet 10/6/13
UK Telegraph

Hit men, drugs and the fall of Ross Ulbricht, the Silk Road 'mastermind' 10/4/13
95.7 KJR: Bob Rivers      

Professor Michael B Taylor on the end of Silk Road (10 min spot) 10/3/13
Los Angeles Times End of Silk Road for drug users as FBI shuts down illicit site
Note: Misquoted. Didn't say "disagree with his con";
I said "we are uneasy with the moral implications of his actions."
10/2/13
Newcastle Herald

The end of the Silk Road paved with gold 10/5/13
Times of Mumbai

Hit men, drugs and the fall of Ross Ulbricht 10/4/13
Sep 2013 I helped a reporter from the Wall Street Journal put together this front page article on Bitcoin mining.
Sep 2013 New CASES paper, Bitcoin and the Age of Bespoke Silicon.
Sep 2013 New IEEE Micro paper, A Landscape of the New Dark Silicon Design Regime.
May 2013
My PhD student, Jack Sampson -> tenure-track assistant professor @ Penn State.
My PhD student, Saturnino Garcia -> tenure-track assistant professor @ University of San Diego.
Jan 2013
C-FAR Logo My lab is now sponsored by DARPA StarNet's $28 Million C-FAR center.
June 2012I presented my paper Is Dark Silicon Useful?
Harnessing the Four Horsemen of the Coming Dark Silicon Apocalypse
(slides) at DAC 2012 and DaSi 2012.

November 2012Quoted in this article in the November 2012 IEEE Computer Magazine on Exascale computing.
May 2012Quoted right at the beginning of this May 2012 IEEE Computer Magazine Article on Dark Silicon, right after Bill Dally! GreenDroid and Conservation Cores get a big shout-out for being a key approach for attacking the Dark Silicon problem.
March 2011 GreenDroid IEEE Micro article, The GreenDroid Mobile Application Processor: An Architecture for Silicon's Dark Future now available!
Nov 2010 UCSD ACM Programming Team, which I coach, invited to Worlds in Egypt!
Aug 2010 We present our GreenDroid mobile application processor design at Hotchips! Our Hotchips work was the only academic talk in the entire conference.

Broad coverage in the media:


MIT Technology Review App-Specific Processors to Fight Dark Silicon.
EETimes Android processor shines light on dark silicon.
San Diego Tribune UCSD: New technology will extend smartphone battery life.
IEEE Spectrum GreenDroid Application Processor Will Battle Dark Silicon.
Register.co.uk CPU, GPU makers gussie up their wares for Hot Chips.
EETimes Asia UCSD researchers develop efficient app-specific cores.
SlashdotThe Fight Against Dark Silicon.
ExtremeTech.comPost-post-PC:The new materials, tech and CPU designs
Embedded Insights UCSD turns on the light on dark silicon.
Light Reading Chip Design Fights Smartphone Power Limits.
inhabitat 'Dark Silicon' Could Boost Smartphone Battery Life 11X.
Slashdot.org The fight against dark silicon

May 2010 HOTCHIPS paper on our C-core-based chip accepted:
GreenDroid: A Mobile Application Processor for a Future of Dark Silicon.
First conference publication to have dark silicon in the title.
Nov 2009 Just released The San Diego Vision Benchmark Suite, a benchmark for the vision application domain, written in MATLAB and clean C. It's available at parallel.ucsd.edu/vision.
Nov 2009 Our paper, Conservation Cores: Reducing the Energy of Mature Computations, was accepted into ASPLOS.
If you read one architecture paper this year, read this ASPLOS Paper. First paper that describes the utilization wall that is the source of dark silicon, and proposes that heterogeneity is the answer.
July 2009 Successfully passed the FAA written test and landed an airplane four times at Long Beach Airport (LGB)!
June 2009 National Science Foundation CAREER Award: Energy-Efficient Parallel Architectures for Computer Vision.

FAQ


Who came up with the term "dark silicon"?

The first use of the term in print was a quote by Bob Metcalfe in March 1997 in the IEEE Internet Computing magazine. However he was referring to all of the sand in the world that has not yet been turned into chips! The first mention of the term I've seen in its current context was by ARM CTO Mike Muller at ARM techcon in October 2009. I've heard other folks say that the term was used by others in ARM and/or HiPeaC community earlier than then. Although ARM techcon happened after we had submitted our ASPLOS paper in Aug 2009 that discussed the utilization wall, we thought it was genius and decided to use the term in the title of our immediately following Hotchips 2010 paper.

How did our group arrive at the utilization wall which causes Dark Silicon, and specialization as an approach to attacking it?

In 2003, I spent a few months reading 300+ ISSCC and IEDM papers with the goal of comparing the (very different) IBM CMOS7SF and Intel P858 fabrication processes as part of a Raw-versus-Pentium-3 section of the Raw ISCA paper I was working on. I was also trying to understand VLSI scaling better so that we could make better proofs about Raw's optimality.

In 2004, I was trying to come up with some ideas for research as a faculty member. I decided to analyze the scalability of multicore chips like Raw across process generations. Using skills picked up from the study I did for the Raw ISCA paper, I arrived at the conclusion that there was an exponentially worsening power issue with multicore scaling and that the problem was the utilization wall and the dark silicon it creates. The analysis is the same as appears in our subsequent grant proposals and papers.

On the interview trail for faculty positions in 2005, I tried to sell the idea of the utilization wall one-on-one with interviewing faculty and further proposed that the "ugly chip" (a massively heterogeneous design) was a logical response. Most everybody didn't believe me or thought it was a terrible idea (James Hoe of CMU, to his credit, thought it was interesting.).

In 2006, as brand new faculty members, Steve Swanson and I cowrote a peer-reviewed 2006 NSF proposal that outlined the utilization wall and created a plan for exploring massively heterogeneous solutions. (Indeed, Steve named our analysis the utilization wall, and already himself had a CAREER award on software aspects of heterogeneity.)

(Here is a April 2007 snapshot of our public website talking about the utilization wall.)

After one round of rejection by peer review, the proposal was funded. The utilization wall appears in the abstract of our NSF Award in July 2008.

After many paper resubmissions, countless co-advising trials and tribulations, we finally got the utilization wall in peer-reviewed academic literature in this March 2010 ASPLOS paper.

MIT Raw Processor


Raw Chip As one of the lead students in the MIT Raw project, I led the design and implementation of the Raw microprocessor, which targeted the leading VLSI technology of the time. I also contributed heavily to almost all of the software systems that we built to support the microprocessor.

Raw was one of the earliest fabricated multicore processors, with 16 cores on a single die, back in 2002. The purpose of Raw was to demonstrate architectural solutions to scalability problems in modern day microprocessors. The Raw architecture exposes the transistor resources of VLSI chips through the tile abstraction, the pin resources through the I/O port abstraction, and the wiring resources through on-chip networks. Raw was commercialized into the Tilera TILE64 architecture.

Because the Raw architecture exposed the on-chip resources more effectively than existing sequential architectures (for instance the P6 micro-architecture, the basis of the Pentium-M), Raw was able to outperform Intel desktop processors, implemented with better process technology, across a variety of applications.

One of the key ideas that came out of the Raw research was the formulation of the Scalar Operand Network (SON), a unique class of sub-nanosecond network responsible for routing operands between functional units and memories in a distributed microprocessor.

My team implemented the 16-tile Raw microprocessor, shown to the upper-left, in IBM's SA-27E 180 nm 6-layer Cu ASIC process. The 18.2 mm x 18.2 mm chip was, at least at the time, the largest design that the IBM ASIC division had targeted for SA-27E. Each tile contains computing power equivalent to a single-issue pipelined processor. We taped out the chip in August '02, and received prototypes back in late October '02. The motherboard was assembled January '03. A supercomputer prototype, based on 4-chip boards, that scaled to 64 Raw chips (1024-issue) was constructed.

More pictures are available here.


Technology Policy Advocacy


Here are my notes about Getting Interviewed as an Expert on TV, based on my experiences getting interviewed by various newspapers, radio shows, and a live TV news program about Bitcoin and the Silk Road.

Testimony regarding Massachusetts House Bill No. 2743, entitled An Act to Improve Broadband and Internet Security,
at Massachusetts Joint Committee On Criminal Justice on April 2, 2003.

This testimony was referenced by Ed Felton's Freedom to Tinker website and discussed in a law journal article:

"Super-DMCA" Statutes: Putting Hollywood in Charge of Internet Business,
Matthew A. Verga, Wake Forest Intellectual Property Law Journal 104, May 2004.

Mailing Address



Prof. Michael B. Taylor
Center for Computer Science and Engineering
University of California, San Diego
9500 Gilman Drive EBU 3b-3202 MC 0404
La Jolla, CA 92093-0404