The Role of ``Lightweight'' Processing in the Cray Cascade Architecture

David Callahan, Cray

Abstract

Cascade is Cray's DARPA-fund HPCS project to improve productivity of future high-performance systems. A key aspect of this architecture is the introduction of ``lightweight'' processors into the memory system. These processors complement the more traditional ``heavyweight'' processors currently used in Cray systems. This paper discusses the various roles and services provided by these processors in the context of improving both the performance and the programmability of Cascade systems.