SC12 Home > SC12 Schedule > SC12 Presentation - Parallel Geometric-Algebraic Multigrid on Unstructured Forests of Octrees

SCHEDULE: NOV 10-16, 2012

When viewing the Technical Program schedule, on the far righthand side is a column labeled "PLANNER." Use this planner to build your own schedule. Once you select an event and want to add it to your personal schedule, just click on the calendar icon of your choice (outlook calendar, ical calendar or google calendar) and that event will be stored there. As you select events in this manner, you will have your own schedule to guide you through the week.

Parallel Geometric-Algebraic Multigrid on Unstructured Forests of Octrees

SESSION: Fast Algorithms

EVENT TYPE: Papers

TIME: 11:00AM - 11:30AM

SESSION CHAIR: Torsten Hoefler

AUTHOR(S):Hari Sundar, George Biros, Carsten Burstedde, Johann Rudi, Omar Ghattas, Georg Stadler

ROOM:255-BC

ABSTRACT:
We present a parallel multigrid method for solving variable-coefficient elliptic partial differential equations on arbitrary geometries using highly adapted meshes. Our method is designed for meshes that are built from an unstructured hexahedral macro mesh, in which each macro element is adaptively refined as an octree. This forest-of-octrees approach enables us to generate meshes for complex geometries with arbitrary levels of local refinement. We use geometric multigrid (GMG) for each of the octrees and algebraic multigrid (AMG) as the coarse grid solver. We designed our GMG sweeps to entirely avoid collectives, thus minimizing communication cost. We present weak and strong scaling results for the 3D variable-coefficient Poisson problem that demonstrate high parallel scalability. As a highlight, the largest problem we solve is on a non-uniform mesh with 100 billion unknowns on 262,144 cores of NCCS's Cray XK6 ``Jaguar''; in this solve we sustain 272 TFlops/s.

Chair/Author Details:

Torsten Hoefler (Chair) - ETH Zurich

Hari Sundar - University of Texas at Austin

George Biros - University of Texas at Austin

Carsten Burstedde - University of Texas at Austin

Johann Rudi - University of Texas at Austin

Omar Ghattas - University of Texas at Austin

Georg Stadler - University of Texas at Austin

Add to iCal  Click here to download .ics calendar file

Add to Outlook  Click here to download .vcs calendar file

Add to Google Calendarss  Click here to add event to your Google Calendar

Parallel Geometric-Algebraic Multigrid on Unstructured Forests of Octrees

SESSION: Fast Algorithms

EVENT TYPE:

TIME: 11:00AM - 11:30AM

SESSION CHAIR: Torsten Hoefler

AUTHOR(S):Hari Sundar, George Biros, Carsten Burstedde, Johann Rudi, Omar Ghattas, Georg Stadler

ROOM:255-BC

ABSTRACT:
We present a parallel multigrid method for solving variable-coefficient elliptic partial differential equations on arbitrary geometries using highly adapted meshes. Our method is designed for meshes that are built from an unstructured hexahedral macro mesh, in which each macro element is adaptively refined as an octree. This forest-of-octrees approach enables us to generate meshes for complex geometries with arbitrary levels of local refinement. We use geometric multigrid (GMG) for each of the octrees and algebraic multigrid (AMG) as the coarse grid solver. We designed our GMG sweeps to entirely avoid collectives, thus minimizing communication cost. We present weak and strong scaling results for the 3D variable-coefficient Poisson problem that demonstrate high parallel scalability. As a highlight, the largest problem we solve is on a non-uniform mesh with 100 billion unknowns on 262,144 cores of NCCS's Cray XK6 ``Jaguar''; in this solve we sustain 272 TFlops/s.

Chair/Author Details:

Torsten Hoefler (Chair) - ETH Zurich

Hari Sundar - University of Texas at Austin

George Biros - University of Texas at Austin

Carsten Burstedde - University of Texas at Austin

Johann Rudi - University of Texas at Austin

Omar Ghattas - University of Texas at Austin

Georg Stadler - University of Texas at Austin

Add to iCal  Click here to download .ics calendar file

Add to Outlook  Click here to download .vcs calendar file

Add to Google Calendarss  Click here to add event to your Google Calendar