EARLY EXPERIENCES WITH DISTRIBUTED SUPERCOMPUTING ON I-WAY - FIRST PRINCIPLES MATERIALS SCIENCE AND PARALLEL ACOUSTIC-WAVE PROPAGATION

The authors present experiences relating to two simulations running on a dedicated network of supercomputers that are connected and schedule d with I-WAY. Each code uses PVM (parallel virtual machine) as the mes sage-passing layer so that the heterogeneity of the computers becomes transparent. These computationally intensive codes require hundreds to thousands of processors to achieve acceptable performance. The I-WAY testbed provides access to the needed resources by allowing a research er to use a virtual I-WAY machine (VIM), which is a collection of supe rcomputing, visualization, and network resources from around the count ry. The authors slightly modified the PVM to operate within the I-WAY scheduling and authentication mechanisms and present the user with a f amiliar interface to run existing programs on this new testbed. New ch allenges are presented when attempting to write efficient codes for ge ographically distributed computers. The applications presented here we re successfully ported to the current I-WAY environment.