The End of a Computer Era as We Know It: Challenges and Opportunities

When: Friday, February 6, 2015
Where: PGH 232
Time: 11:00 AM

Speaker: Prof. Lennart Johnsson, University of Houston-COSC

Host: Prof. Ioannis Kakadiaris

For over 40 years “Moore’s law” has resulted in a doubling of the number of transistors in a given area for each generation of CMOS technology.  Coupled with Dennard scaling resulting in a 40% performance improvement of a transistor at constant power consumption this resulted in a close to three times performance improvement per CMOS technology generation about every two years. The Dennard scaling ended about a decade ago resulting in the industry turning to multi-core processor designs attempting to continue to offer exponential improvement in processor capabilities. Performance improvements became heavily dependent on parallelism in applications.  With the end of Dennard scaling, fixed power budgets and increased significance of transistor leakage currents, processor designs are now governed by power constraints even for designs targeting the server market and “dark silicon” is becoming a reality as well as refined power management presenting challenges and opportunities for computer architects, algorithm and software designers. The cost metric has changed fundamentally.  We will present the technology background together with our efforts in exploring benefits and challenges of some architectural alternatives to the dominating x86 architecture.

Bio:

Lennart Johnsson is a Hugh Roy and Lillie Cranz Cullen Distinguished University Chair of Computer Science, Mathematics, and Electrical and Computer Engineering. He has served on the faculties of Caltech, Yale , Harvard, and the Royal Institute of Technology and been an adjunct professor at Rice and a visiting professor at Linkoping and Uppsala Universities and a visiting scientist at Argonne National Laboratory and the Institute for Mathematics and its Applications at The Academy of Engineering Sciences, Stockholm, Sweden. He served as Manager of Systems Engineering, Electrical Systems, ABB Corporate Research, and Director of Computational Sciences at Thinking Machines Corp (TMC).

He developed one of the first sparse matrix packages for real-time use and played a leading role in developing systems for real-time supervisory control and data acquisition at ABB Research making ABB a world leader of such systems. He led the development of Scientific Software Libraries at TMC and significantly influenced the Run-Time System for the Connection Machine systems. His work with students on computer systems communication algorithms contributed to the collective communications primitives in the MPI standard. He developed and introduced the first courses on parallel scientific and engineering computing at Caltech, Yale and Harvard. Prof. Johnsson led the establishment of the Texas GigaPoP, one of the first in the US, the participation in the first Globus testbed covering five continents, the creation of a distributed storage network at UH, and the Research and Education Network of Houston (RENOH), a fiber network connecting UH main, downtown and Victoria campuses, Rice, Texas Southern University, and the Texas Medical Center with Internet2 and NLR.

Prof. Johnsson’s research on energy efficient computer system design, operation and programming, including HPC data center energy efficiency and recovery has resulted in an energy efficiency blade server produced by Supermicro and a data center heat recovery system. He is currently exploring the energy efficiency of DSPs for HPC workloads together with Texas Instruments and students at the Royal Institute of Technology, and of a mobile video processor together with Movidius and collaborators at the University of Chicago. He is an editor of the journal Concurrency and Computation: Practice and Experience, the International Journal of High-Performance Computing and Applications, the International Journal of High Performance Computing and Networking and the journal for Sustainable Computing: Informatics and Systems. He has served on more than 60 organizing and program committees for conferences and symposia.