What's on the floor?

An overview of NCAR computing resources, spring 1996

Compiled by Susan Albertson

• Introduction
• General Community resources: Serving a wide range of users
• ACE: Large simulations in support of climate research
• Comparison of Cray Parallel Vector Processor Machines

Introduction

The NCAR supercomputing facility is divided into two components: General Community computing resources and the Accelerated Computing Environment (ACE), as shown in this functional diagram.

General Community resources: Serving a wide range of users

General Community computing resources provide reliable, general-purpose computing power to university and NCAR researchers in the areas of climate, weather prediction, oceanography, upper atmosphere studies, mesoscale and microscale meteorology, basic fluid dynamics, astrophysics, cloud physics, and miscellaneous applications. The following equipment is available to the General Community:

• The CRAY Y-MP8/864 (shavano)
• The CRAY J916 (paiute)
• The IBM RS6000 cluster
• The front-end computer--Sun-SPARCserver (meeker)

"We offer the General Community gigaflop sustained performance via multitasking on either the Y-MP or the J9," says SCD Director Bill Buzbee. "About 20% of shavano's cycles are now being used by jobs in the ND (near dedicated) queue, which is good for performing multitasked jobs. The the J9 can also be used for multitasking." (For more on getting the most out of General Community resources, see "CRAY J9: A good deal for single-processor, large-memory jobs" and "Choose paiute over shavano for large-memory jobs," in this issue of SCDzine.

To use the General Community equipment, a researcher must obtain an allocation of General Accounting Units (GAUs). Allocation of computing resources to university scientists is done by a peer review process. Charging for General Community resources is based on priority queues.

ACE: Large simulations in support of climate research

The Accelerated Computing Environment, or ACE, is dedicated to a small number of activities that involve large simulations in support of climate research. In particular, ACE supports the new U.S.Global Change Research Program (GCRP) multiagency Climate Simulation Laboratory (CSL). The CSL provides over 10,000 equivalent Y-MP CPU hours per month to 11 GCRP proposals. ACE also supports international interdisciplinary projects and research conducted under the guidelines of NSF's HPCC (High Performance Computing and Communications) program.

The following equipment is available to ACE users:

• The CRAY Y-MP8/8I (antero)
• The CRAY T3D/MCA64
• The CRAY J920 (aztec)
• The CRAY EL98 (st-elmo)

Allocation and charging processes for ACE are separate from those of the General Community.

Comparison of Cray Parallel Vector Processor Machines

     Current lineup of Cray PVP (Parallel Vector Processor) machines

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                     Main    UNICOS	     Mem    SSD    Clock   Mflops/
Name      Model   Purpose   Version   CPUs   (mw)   (mw)   (nsec)     CPU
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shavano     YMP   General     8.0.4     8     64    256        6      333
paiute      J90   General     8.0.4    16    256      0       10      200

antero      YMP       ACE     8.0.4     8     64    256        6      333
aztec       J90       ACE     8.0.4    20    512      0       10      200
st-elmo      EL       ACE     8.0.4     8    256      0       30       66

echo         EL      TEST     9.0.22     2     64      0       30       66
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