SEECS Colloquium

We show how key insights from our research into active memory systems, coupled with emerging trends in commodity network technology, are leading toward the realization of hardware distributed shared memory (DSM) on clusters of industry-standard workstations. We call the result of this convergence active memory clusters. After discussing the current state of the art in hardware DSM, clusters, and software DSM architectures, we highlight the key differences between hardware and software DSM systems and show how these differences are rapidly disappearing in commodity systems---with the notable exception of the specialized memory controller present in hardware DSM systems. We then discuss our recent research results in active memory systems showing that our active memory controller design increases single-node performance. These results argue for the inclusion of active memory support in forthcoming commodity workstations. We show that active memory support can be treated as an extension of the cache coherence protocol, and that an active memory controller also contains the necessary functionality for building a hardware DSM machine. Coupled with enhancements in network technology and a small amount of software support, active memory clusters can achieve hardware DSM performance on next-generation commodity servers.

Mark Heinrich is an Assistant Professor in the School of Electrical and Computer Engineering at Cornell University, a co-founder of its Computer Systems Laboratory, and a member of the Intelligent Information Systems Institute. His research interests include active memory and I/O systems, parallel computer architecture, system-area networks, novel computer architectures, embedded architectures, scalable cache coherence protocols, multiprocessor design and simulation methodology, and hardware/software co-design. He received his Ph.D. in Electrical Engineering in 1998 from Stanford University under John Hennessy where he was a principal designer of the FLASH multiprocessor. He received his MS from Stanford in 1993, and his BSE in Electrical Engineering and Computer Science from Duke University in 1991. Dr. Heinrich was also the co-founder and Chief Architect of Flashbase, Inc. an Internet company specializing in automated sweepstakes and database-backed forms and tools for customer acquisition. Flashbase was acquired by DoubleClick Inc. in May 2000.