NERSCPowering Scientific Discovery for 50 Years


  IBM Compiler Optimization Options

Download File: optarg.ppt | ppt | 53 KB

All of the IBM supplied compilers produce unoptimized code by default. Specific optimization command line options must be supplied to the compilers in order for them to produce optimized code. In this talk, several of the more useful optimization options for the IBM Fortran, C, and C++ compilers are described and recommendations will be given on which of them are most useful.

  Performance profiling using hpmcount, poe+ and hpmlib

Download File: profiletml.ppt | ppt | 205 KB

  SvPablo and the PERC Performance Tool Suite

Download File: NUGSvPabloPERCcorrect.ppt | ppt | 809 KB

It is clear that we gain a great savings by analyzing and tuning our codes. To be effective in our efforts to improve performance, we need a versatile, robust, and portable set of performance tools. The NERSC/LBNL-led Performance Evaluation Research Center (PERC) SciDAC project is developing an interoperable suite of measurement, analysis, and tuning tools to respond to this need. The PERC tool suite features an infrastructure of low-level APIs, and a set of end-user tools built on top of those APIs. In this talk we discuss the PERC tool infrastructure and take an in-depth look at the SvPablo tool for performance instrumentation and browsing. We will also look at the future roadmap for the PERC tools and at how the PERC tool suite will affect the the future of performance analysis and tuning.

  Scaling Up Parallel I/O on the IBM SP

Download File: ScalingGPFS.ppt | ppt | 1.2 MB

Several strategies for parallel I/O are presented and compared. Evaluation of of the best strategies for a given total data size and MPI concurrency is presented.

  Debugging, Reactively and Proactively

Download File: TOTALVIEW3.ppt | ppt | 958 KB

Totalview is an essential tool for debugging codes. This talk will focus on the usage of totalview with FORTRAN and C/C++. Many examples will be provided to show how to use this tool effectively. Examples using MPI, OpneMp will be provided.

  Practicing Safe Computing at NERSC

Download File: NUG.Security.Talk.June.2002.ppt | ppt | 406 KB

Computer security is a vast topic, however this talk will give an overview of the inherent threat level currently on the Internet, how computer security is done at NERSC and techniques you can employ to ensure your computing experience at NERSC is a safe and secure one.

  File and data conversion

Download File: convert.ppt | ppt | 152 KB

After the decommissioning of the Crays, what will become of the all the data stored in Cray unformatted files? In this talk we will review some of the options available in Cray's Flexible File I/O library that enable Cray files and data to be converted to formats usable on the IBM SP. Also, there will be an overview of the NCARU library, available on the SP, which has similar capabilities.

  Scaling Up MPI Applications

Download File: ScalingMPI.ppt | ppt | 143 KB

Problems unique to large concurrency MPI applications are presented along with means for addressing the problems. An overall approach to dealing with scaling issues is presented along with a set of frequently encountered problems.

  A Report on the ACTS Toolkit

Download File: NUG.1.ppt | ppt | 956 KB

The ACTS (Advanced Computational Testing and Simulation) Toolkit is a set of computational tools developed primarily at DOE laboratories and is aimed at simplifying the solution of common and important computational problems on parallel machines. The tools fall into four broad categories: numerical, and support for code development, execution and library development. In the talk we will describe the tools currently installed on NERSC platforms and the levels of support provided to users.

  NERSC Software Roadmap

Download File: NERSCSW.ppt | ppt | 160 KB

Details of seaborg's transition to AIX 5.1, compiler upgrades, and NERSC application software changes will be given. Specific attention will be given to 64 vs. 32 bit issues.

  ACTS Tools - Case Studies with User Codes

Download File: NUG.2.ppt | ppt | 2.2 MB

As a follow-up for the report on the ACTS Toolkit, in this talk we will show examples of how ACTS tools have been used on NERSC platforms and discuss lessons that we have learned.

  Introducing Juan Meza - the new head of NERSC HPC Research Dept

Download File: NUG.060302.ppt | ppt | 471 KB

  Update on security issues with FTP

Download File: NUGMeetingFTPUpdateJune2002.ppt | ppt | 62 KB

  FY 2003 Allocations

Download File: FY2003AllocationProcess.ppt | ppt | 82 KB

  Visualization Update (1 of 2)

Download File: NUG060302-ks.ppt | ppt | 3.4 MB

(See Visualization update (2 of 2) for movies by Ken Schwartz)

  Visualization Update (2 of 2)

Download File: y-py.mpg | mpg | 4.2 MB
Download File: parvin.mpg | mpg | 914 KB
Download File: surfx.mpg | mpg | 567 KB

Includes movies associated with this presentation, created by Ken Schwartz

  NERSC “Visualization Greenbook”: Future Visualization Needs of the DOE Computational Science Community Hosted at NERSC

Download File: VisGreenFindings-LBNL-51699.pdf | pdf | 2.8 MB

This report presents the findings and recommendations that emerged from a one-day workshop held at Lawrence Berkeley National Laboratory (LBNL) on June 5, 2002, in conjunction with the NERSC User Group (NUG) Meeting.