Several high-performance computers now use field-programmable gate arrays as reconfigurable coprocessors. The authors describe the two major contemporary HPRC architectures and explore the pros and cons of each using representative applications from remote sensing, molecular dynamics, bioinformatics, and cryptanalysis.

Modern Graphic Processing Units (GPUs) are widely used as application accelerators in the High Performance Computing (HPC) field due to their massive floating-point computational capabilities and highly data-parallel computing architecture. Contemporary high performance computers equipped with co-processors such as GPUs primarily execute parallel applications using the Single Program Multiple Data (SPMD) model, which requires balanced computing resources of both microprocessor and co-processors to ensure full system utilization. While the inclusion of GPUs in HPC systems provides more computing resources and significant performance improvements, the asymmetrical distribution of the number of GPUs relative to the microprocessors can result in an underutilization of overall system computing resources. In this paper, we propose a GPU resource virtualization approach to allow underutilized microprocessors to share the GPUs. We analyze factors affecting the parallel execution performance on GPUs and conduct a theoretical performance estimation based on the most recent GPU architectures as well as the SPMD model. Then we present the implementation details of the virtualization infrastructure, followed by an experimental verification of the proposed concepts using an NVIDIA Fermi GPU computing node. The results demonstrate a considerable performance gain over the traditional SPMD execution without virtualization. Furthermore, the proposed solution enables full utilization of the asymmetrical system resources, through the sharing of the GPUs among microprocessors, while incurring low overheads due to the virtualization layer.

Contemporary quantum computers face many critical challenges that limit their usefulness for practical applications. A primary limiting factor is classical-to-quantum (C2Q) data encoding, which requires specific circuits for quantum state initialization. The required state initialization circuits are often complex and violate decoherence constraints, particularly for I/O intensive applications. Existing Noisy Intermediate-Scale Quantum (NISQ) devices are noise-sensitive and have low quantum bit (qubit) counts, thus limiting the applicability of C2Q circuits for encoding large and realistic datasets. This has made the study of complete and realistic circuits that include data encoding challenging and has also led to a heavy dependency on costly and resource-intensive simulations on classical platforms. In this work, we propose a cost-effective, classical-hardware-accelerated framework for realistic and complete emulation of quantum algorithms. The emulation framework incorporates components for the critical C2Q data encoding process, as well as architectures for quantum algorithms such as the quantum Haar transform (QHT). The framework is used to investigate optimizations for C2Q and QHT algorithms, and the corresponding optimized quantum circuits are presented. The framework is implemented on a High-Performance Reconfigurable Computer (HPRC) which emulates the proposed QHT circuits combined with proposed C2Q data encoding methods. For performance benchmarks, CPU-based emulations and simulations on a state-of-the-art quantum computing simulator are also carried out. Results show that the proposed hardware-accelerated emulation framework is more efficient in terms of speed and scalability compared to CPU-based emulation and simulation.

Runtime Reconfiguration (RTR) has been traditionally utilized as a means for exploiting the flexibility of High-Performance Reconfigurable Computers (HPRCs). However, the RTR feature comes with the cost of high configuration overhead which might negatively impact the overall performance. Currently, modern FPGAs have more advanced mechanisms for reducing the configuration overheads, particularly Partial Runtime Reconfiguration (PRTR). It has been perceived that PRTR on HPRC systems can be the trend for improving the performance. In this work, we will investigate the potential of PRTR on HPRC by formally analyzing the execution model and experimentally verifying our analytical findings by enabling PRTR for the first time, to the best of our knowledge, on one of the current HPRC systems, Cray XD1. Our approach is general and can be applied to any of the available HPRC systems. The paper will conclude with recommendations and conditions, based on our conceptual and experimental work, for the optimal utilization of PRTR as well as possible future usage in HPRC.

High-performance reconfigurable computers (HPRCs) are parallel computers but with added FPGA chips. Examples of such systems are the Cray XT5_h and Cray XD1, the SRC-7 and SRC-6, and the SGI Altix/RASC. The execution of parallel applications on HPRCs mainly follows the single-program multiple-data (SPMD) model, which is largely the case in traditional high-performance computers (HPCs). In addition, the prevailing usage of FPGAs in such systems has been as co-processors. The overall system resources, however, are often underutilized because of the asymmetric distribution of the reconfigurable processors relative to the conventional processors. This asymmetry is often a challenge for using the SPMD programming model on these systems. In this work, we propose a resource virtualization solution based on partial run-time reconfiguration (PRTR). This technique will allow sharing the reconfigurable processors among the underutilized processors. We will present our virtualization infrastructure augmented with an analytical investigation. We will verify our proposed concepts with experimental implementations using the Cray XD1 as a testbed. It will be shown that this approach is quite promising and will allow full exploitation of the system resources with fair sharing of the reconfigurable processors among the microprocessors. Our approach is general and can be applied to any of the available HPRC systems.