Scientific Computing Seminar

Date:

Tuesday, July 26, 2005

Time:

10:00am-11:00am

Location:

50B-4205

Seminar Speaker:

Christian Bell
UC Berkeley
http://www.cs.berkeley.edu/~csbell/

Title:

Using Overlap to Reduce Bisection Bandwidth Needs with Berkeley UPC

Abstract:

This talk focuses on overlap techniques using one-sided communication in UPC and in particular, employing Berkeley's UPC extensions to reduce the importance of bisection bandwidth in problems traditionally viewed as bandwidth bound. GASNet, the communication system targeted by Berkeley UPC, is designed to allow for portable yet high-performance one-sided asynchronous communication across the entire range of network message sizes. As a result, application programmers can employ parallel programming techniques not typically prescribed to message-passing programmers and reap performance speedups of up to 50% on application benchmarks such as NAS FT. The talk begins with a quick overview of UPC and GASNet, including some of the research and implementation efforts that allow GASNet to provide significant communication performance improvements over MPI. We then argue that GASNet's design goals to match modern hardware characteristics give an opportunity for application programmers to leverage the programmability advantages in UPC and the one-sided programming model to make more efficient use of their networking and computational resources.

Sponsor of Seminar:

Kathy Yelick

Scientific Computing

Contact Esmond G. Ng EGNg@lbl.gov