Presented by Visualization at the Leadership Computing Facility Sean Ahern Scientific Computing Center for Computational Sciences

2 Ahern_LCFViz_0611 Statistical Analysis of Fusion Eddy Formation Principal Component Analysis allows isolation of rotational modes of eddy evolution

3 Ahern_LCFViz_0611 Visualization of Neutron Density Fields  Joint work between ORNL and Oxford University has developed a model of nuclear matter in the transitional density region between inhomogeneous matter, containing nuclei and nucleons, and homogeneous matter, consisting of uniformly distributed nucleons, in collapsing stars.  We developed custom visualization techniques for analyzing the spatially varying distribution of nucleon densities.

4 Ahern_LCFViz_0611 Statistics and Visualization for Climate Simulation Volume visualizations of the simulated time evolution of land and ocean components of atmospheric CO 2 concentrations originating from the ocean surface were produced to help climate scientists examine the influence of climate variability, prescribed atmospheric CO 2 levels, and land cover change on terrestrial carbon fluxes during the 20th century. Data from Phase I of the CCSM LCF Computational Climate Science End Station (CCSES)

5 Ahern_LCFViz_0611 EVEREST Facility  35 million pixel, 27-tile Powerwall  30’ x 8’  14 NVIDIA 3000G GPUs  Interactive, large-scale, collaborative data analysis  Open source and custom software  DMX, Chromium, PixelBlaster, Blockbuster, etc. 5 Ahern_LCFViz_0611

6 Ahern_LCFViz_0611 Title Visualization Architectures for Tera/Petascale Visualization  Largest datasets require use of institutional resources  Reduces data movement issues  Allows exploitation of multiple GPUs  Provides visualization to remote users  Exploited by VisIt, ParaView, EnSight

7 Ahern_LCFViz_0611 Technology Curve Mismatches  Processor speeds (and FLOPS) are going up (60%/year)  Interconnect speeds are going up  Graphics card performance is going up (100%/year)  Increased computational ability won’t solve issues – can’t just ride processor speed curves  In some cases, users are not willing to move or post-process their data for visualization Data Access Patterns are Important!  Memory-to-memory copy hasn’t kept up (5-10%/year)  Disk access time hasn’t kept up (5-10%/ year)  Increasing bottleneck to data processing  I/O can often be the most expensive phase of simulation or post-processing WinProblems

8 Ahern_LCFViz_0611 Summary and “Info-vis” techniques  Increasing need to compare datasets  Parameter studies  2D/3D simulation correlations  Direct visual comparison often inadequate  Different mesh types, codes  High-dimensional datasets are becoming much more common  “Information-driven” interaction  Contour spectrum  Topology graphs/trees  Topology methods  Distance fields  Shape characterization  Information visualization techniques

9 Ahern_LCFViz_0611 Chromium RenderServer  Remote image delivery  OpenGL and X11 paths  Collaborative  Supports tiles  Leverages:  Chromium  VNC  DMX  Small Business Technology Transfer program – DOE STTR Render Server to Both Local and Remote Viewers

10 Ahern_LCFViz_0611 Up and Coming Technologies… (and some already here)  Office “mini-clusters”  Vendor-integrated vis clusters  Very high resolution displays  Sony 4K projector  Multi-GPU systems  “Cell” processor  “Commodity” constellations with GPUs

11 Ahern_LCFViz_0611 Contact Sean Ahern Scientific Computing Center for Computational Sciences (865) Ahern_LCFViz_0611