Charles Tong

ASCR Requirements Worksheet

1.1. Project Information - Uncertainty quantification for NNSA applications

2. Project Summary & Scientific Objectives for 2011-2014

Please give a brief description of your project - highlighting its computational aspect - and outline its scientific objectives for 2011-2104. Please list one or two specific goals you hope to reach by 2014.

Project: Perform extensive uncertainty quantification on multiphysics models in NNSA applications to enhance the predictive capabilities of the models 

2011-2014 objectives: 

The whole project consists of several pegposts, with the first two to be achieved by 2014. 

Goal: to develop and demonstrate a comprehensive UQ methodology for the project

3. Current HPC Usage and Methods

3a. Please list your current primary codes and their main mathematical methods and/or algorithms. Include quantities that characterize the size or scale of your simulations or numerical experiments; e.g., size of grid, number of particles, basis sets, etc. Also indicate how parallelism is expressed (e.g., MPI, OpenMP, MPI/OpenMP hybrid)

Primary codes: LLNL multiphyiscs codes 

 Each simulation takes 2-12 hours on 128 processors, use MPI 

 Need thousand of runs 

3b. Please list known limitations, obstacles, and/or bottlenecks that currently limit your ability to perform simulations you would like to run. Is there anything specific to NERSC?

Machine availability, code robustness, job scheduling and storage management, fault detection and recovery 

3c. Please fill out the following table to the best of your ability. This table provides baseline data to help extrapolate to requirements for future years. If you are uncertain about any item, please use your best estimate to use as a starting point for discussions.

Please list any required or important software, services, or infrastructure (beyond supercomputing and standard storage infrastructure) provided by HPC centers or system vendors.

4. HPC Requirements in 2014

4a. We are formulating the requirements for NERSC that will enable you to meet the goals you outlined in Section 2 above. Please fill out the following table to the best of your ability. If you are uncertain about any item, please use your best estimate to use as a starting point for discussions at the workshop.

4b. What changes to codes, mathematical methods and/or algorithms do you anticipate will be needed to achieve this project's scientific objectives over the next 5 years.

4c. Please list any known or anticipated architectural requirements (e.g., 2 GB memory/core, interconnect latency < 1 μs).

4d. Please list any new software, services, or infrastructure support you will need through 2014.

4e. It is believed that the dominant HPC architecture in the next 3-5 years will incorporate processing elements composed of 10s-1,000s of individual cores, perhaps GPUs or other accelerators. It is unlikely that a programming model based solely on MPI will be effective, or even supported, on these machines. Do you have a strategy for computing in such an environment? If so, please briefly describe it.

New Science With New Resources

To help us get a better understanding of the quantitative requirements we've asked for above, please tell us: What significant scientific progress could you achieve by 2014 with access to 50X the HPC resources you currently have access to at NERSC? What would be the benefits to your research field if you were given access to these kinds of resources?

Please explain what aspects of "expanded HPC resources" are important for your project (e.g., more CPU hours, more memory, more storage, more throughput for small jobs, ability to handle very large jobs).