Special Issue: Exploring the Frontiers of Computing Science and Technology: Adapting Emerging Multi‐ and Many‐core Processors

Abstract

Recent trends in computer microprocessor development have shifted from a single powerful core to multi- and many-cores. As a result, the continuous improvement in computing power fueled by the exponentially increasing speed of a single processor could be over. With applications such as Earth and space sciences, higher resolutions and more sophisticated treatments of physical processes make models even more computationally intensive. Moreover, the drastic increase of data collected by various instruments requires a significant increase in computing power for data processing and analysis. Therefore, it is crucial for the computational science and technology community to evaluate the impacts of this shift on computationally intensive modeling and data processing applications and to develop appropriate solutions. It is known that the computing power of conventional processors is limited by memory bandwidth. Adding more cores to the processors worsens the problem. It is necessary to adapt computing algorithms to effectively utilize the computing power of those conventional multi- and many-core processors. In the last two years, there have emerged few unconventional processors: IBM's Cell Broadband Engine (hereafter referred to as Cell) and NVIDIA's Graphics Processing Unit (GPU). Intel and AMD are also developing competing Cell- or GPU-like processors, in addition to conventional multi- and many-core processors. It has been demonstrated that certain computationally intensive applications with moderate data communication can benefit from both Cell and GPU with a significant performance improvement. However, these emerging processors require new programming paradigms, which increase the porting costs and impede their effective utilization. To address such issues with the unconventional multi- and many-core processors, this special issue assembles some of the latest research on assessing the impacts of multi- and many-core processors, developing appropriate solutions, and taking advantage of the abundant computing power. The invited papers in this special issue represent augmented works originally presented at the Frontiers of Multicore Computing Conference 2008, held at the University of Maryland, Baltimore County in August 2008. Of course, it is not possible for a single issue to include all the topics addressed by the conference. However, the selected papers cover representative research addressing the issues above. There are four and two papers addressing the issues related to Cell and multi-core processors, respectively. The paper by Germann et al. presents their approaches and optimization methods in porting a short-range parallel molecular dynamics code to the first petaflops computer, Roadrunner, which uses Cells as accelerators 1. The paper by Woodward et al. reports their initial experience with porting and optimizing gas dynamics simulation on Roadrunner 2. The paper by Zhou et al. presents a study on the impact of Cell on the programming paradigm for climate and weather models 3. The paper by Brown et al. presents a contemporary artwork, the ‘Scalable City,’ accelerated with Cell 4. The paper by Wang and JaJa presents a study on interactive direct volume rendering with Intel Clovertown quad-core processors 5. The paper by Simmon and McGalliard provides benchmark results for a variety of high-performance computing applications on the Cray XT3 and XT4, which use dual- and quad-core AMD Opteron processors, and discusses and analyzes multi-core effects 6. The guest editors of this special issue would like to express their deep gratitude to all authors, external reviewers, and Geoffrey Fox for their efforts in making this issue possible.